Whenever Yuki Kajiura and the strings and chimes of Awesome strike up, not only is the unkillable going to be killed, it's going to be spectacular.
The Slayers: Lina has the same music anytime she casts Dragon Slave (and Giga Slave and Laguna Blade). Also somewhat distorted on the Battle Music (same every time — ikinashi oodate) and totally distorted for Amelia and Gourry (with douchuuki).
Slayers Evolution-R has a variation on the "series theme plays as Big Bad gets ass handed to him" thing, playing the theme from Next.
A bit different in the final season, in which the new addition to the cast — the Sailor Starlights — had an appearance theme very different to the traditional "sudden and loud" ones: starting quiet and subtle and then getting louder during the close-up on them.
The English-dubbed version of the Season 1 finale features "Carry On" during the final battle, one of the very few improvements over the Japanese original (the original used the full-length opening song "Moonlight Densetsu"). Other songs featured are "Ai no Senshi", "La Soldier" (from the Sailor Moon R finale), and "Moon Revenge" (from the R movie). The last episode of Sailor Stars uses the season's opening "Sailor Star Song" in this manner.
Ichigo of Bleach; whenever he was about to kick serious ass, his Image Song ("Number One" by Hazel Fernandez) would kick in. This was subverted at one point: Ichigo moves to attack an unusually powerful badass, and his Theme Music Power-Up stops almost as soon as it starts when his opponent blocks the attack with a single finger. Yeah, that's right... Aizen is so tough he can even defeat your theme music.
As this video shows, "Number One" did provide a Theme Music Power-Up, but for the wrong character. "Number One" allows Renji to display some awesome, but as soon as Ichigo jumps into action, the fickle theme song is cutdown by Aizen's finger of doom.
Ironically, the first proper use of the Image Song in the series was when it was used by the series' Fake Ultimate Hero to rescue Ichigo with his "Ultimate Attack".
More recently, the Big Bad and/or his Arrancar get classy, suspenseful Latin-style music in the background whenever they're making a grand entrance or are about to kick big-time ass. (This is in keeping with their Spanish-tinted theme.)
Number One returns in a rock form called Chokkaku when Ichigo returns from his little training exercise in the Dangai. The very next action involves Aizen talking shit, then getting grabbed by the face and forcefully removed from the scene. It's safe to say its power returned.
Guilty Crown does this when the main character gets his powers at the end of the first episode, with a song called Bios, composed by the wildly popular J-Pop band Supercell and sung in Gratuitous German. Don't let the mangled pronunciations get you; it's only because the singer is Japanese. Take a good look at the actual lyrics and you'll see that not only is the German grammar flawless, but the lyrics also allude to the ordeals the characters in the actual show face. As of winter 2011, there were also several cases of Autobots, Rock Out!, and at that point the show was only halfway through season one.
One shot even has Kirika wait to shoot the guy until the music finishes.
Similarly, anytime you start to hear Yanmaani (the song's title is "Nowhere") in the background in Madlax, the titular character is about to kick serious amounts of ass with inhuman skill. It's so prevalent that The Other Wiki even mentions it. It is a joke among fans that the word gives Madlax super powers.
Saiyuki has the OP theme "For Real"; it's not surprising that the rockin' guitar version brings the pain to you, but what's more interesting is that the gentle, tinkling piano version can either be the theme to character growth and introspection... or the warning that Genjo Sanzo is about to deliver a No-Holds-Barred Beatdown on whoever's in his way — complete with some snarky deconstruction of whatever BS the poor yutz was trying to spout at the time.
Yu-Gi-Oh! has the show's main theme begin to play pretty much every time Yugi pulls off an epic combo. The theme of the Egyptian God cards plays whenever one of them is summoned.
In the first season's English dub, Kaiba's theme, "I'm Back," plays in a few choice Theme Music Power-Up spots.
During episodes 18 and 19 of the GX dub, the duelist who purloined Yugi's deck and was dueling Jaden kept having musical overtures from the previous series playing. Towards the end, they were even being played in the same musical style as a lot of GX music.
Yu-Gi-Oh! 5Ds has a variety, kicking off with Jack Battle in the very first episode when he summons Red Demons in a televised duel, then got upgraded to an early and unreleased track when summoning Savior Demon Dragon that goes under the Fan NicknameJack Battle 2. Yusei has his own themes, Yusei Battle 2 usually reserved for whenever he whips out Savior/Star Dragon. As of late, with Accel Synchros coming into play, a couple of occasions featuring Yusei summoning Shooting Star Dragon are accompanied by Clear Mind sung by Masaaki Endoh.
Dokkoida?! hangs a Lampshade on this; the hero's power suit is able to induce this state by playing a heroic theme song. At least if the company that made the suit actually got that feature working before they released it. But the hero doesn't know that, and he manages to get the same effect just from suggestion and enjoying the Hot Blooded music.
Pretty much every evolution sequence in every season of Digimon adheres to this trope. The more absurdly powerful the evolved form is, the more obnoxious and high-pitched the theme music will be, whereas less impressive evolutions (compared to the one available to the main character's partner at any given point in the series) often go by without music altogether. Also, true to this trope, evolution music invariably stops as soon as the evolved Digimon is hit by it's enemy.
A good example occurs in the Adventure movie, Bokura No War Game. The evolution song, 'Brave Heart', plays throughout one of the battle scenes, and when Patamon tries to digivolve to his Adult/Champion level, he is attacked, at which point the music cuts out suddenly. It resumes around 30 seconds later when Taichi and Yamato's Digimon charge to counter attack. And then, before the computer crashes on Taichi, the line 'SHOW ME YOUR BRAVE HEART!' skips and replays several times, cutting out when the computer gets the BSoD.
Another example of the above happens in the episode where Greymon dark digivolves into SkullGreymon. During the battle scene, Brave Heart plays as normal, but a few seconds into the evolution scene, the song fades into a really dark and sinister piece of BGM.
And in Adventure, we have "Hey Digimon". It plays, then you're screwed.
The American Digimon movie had a fairly good example in the first half. after the swarm of Diaboromons blast Wargreymon and Metalgarurumon into submission, the scene where the two digimon fuse into Omnimon was accompanied with a Spine Chilling rendition of the Digimon theme. However, the movie took a different route with the actual fight scene, which was treated to a ear-rendingly bad licensed pop-rock song that is completely at odds very different but still equally good song that still fits with the Curb-Stomp Battle being shown.
Another The Movie dub example: the fight between Parrotmon and Greymon. 15 minutes in and with only a narmy rap remix of the theme heard so far, Greymon introduces himself to Tai. The distant sound of records scratching echoes across the 5.1, and three glorious almost-words, despite being only whispered, are still louder than the biggest explosion: "DI- DI- DI-..."
From the same fight, after Greymon blacks out (Parrotmon is a level higher than Greymon, so he's having some trouble) Tai uses the whistle to wake him up for round two. We don't hear too much of the song, as round two is much shorter.
Cardcaptor Sakura seems to have a leitmotif that appears on the soundtrack whenever she finally joins battle with a particularly powerful enemy. (If you've seen the show, you'll recognize it as a disco-style instrumental with oddly majestic sweeping strings playing the melody.)
Various versions of a heavy, hot-blooded rap song are played during pivotal power-up moments in Tengen Toppa Gurren Lagann. Eventually they get so powerful that they actually get those lyrics superimposed on an opera track.
Tengen Toppa Gurren Lagann plays this down to the very basis of each part of the trope. There's the various power-up versions of 'Rap Is A Man's Soul!'(AKA 'ROW ROW FIGHT DA POWAH') One for Kamina, one for Gurren-dan, after Kamina's death, and "Libera Me From Hell". Along with these are 'Ten Wo Tsuke/Pierce the Heavens With Your XXX!' (Occurs in Episodes 1 and 8, when they first break through to the surface and the first Giga Drill Breaker), "Happily Ever After" (Insert Song, used in Episode 11 when Simon has his famous He's Back moment), and the full version of the show's theme, Sora Iro Days, used when the cast fight on top of galaxies against the Anti-Spiral.
Also works for the bad guys: whenever Viral shows up and does something awesome, the Surprisingly Good English song "Nikopol" plays. The meaning of the title Nikopol coming from the greek as Nikę meaning victory and polis which is city. "City of victory" sounds very ironic when you realize how this guy keeps losing to the good guys every single time. But he never gives up, eventually joins the good guys, and lands up being immortal and apparently very happy as an ambassador of the Earth. He won after all.
Subverted in episode 25 where an attack is launched, a power up song starts... and the missile is harmlessly crushed before it can reach its destination. In all fairness, that wasn't the main theme song anyway.
Then played straight immediately after.
In episode 2, when Kamina and Simon hijack the Gunzan, later named Gurren, the Surprisingly Good English song "Gattai Nante Kusokurae" (AKA "To Hell with Gattai") starts playing.
It plays during the final battle with Lordgenome as well, when Simon is reduced to fighting the Spiral King's Gurren Lagann-style mech with just his own Lagann, and totally kicks ass.
During the final battle with the Anti-Spiral in the second movie, a new version of Sora Iro Days plays. It blows away the series final battle in sheer awesomeness and badassery, and must be seen/heard to be comprehended.
Futari wa Pretty Cure: Nagisa and Honoka are undefeatable when the instrumental version of the theme song is playing. And if the background music has lyrics, they can accomplish miracles like defeating Jaaku King or getting Kiriya to turn good. At the end of Futari Wa Pretty Cure Max Heart, the theme song was played with lyrics, which was both at once and thus gave Pretty Cure the ability to defeat the Jaaku King for real this time.
Heartcatch Precure has "Heart Goes On" for its big moments. However, the first time it was played, it was rather tame - a combined musical concert and fashion show. The next two times it's played (after Cure Blossom passes the Final Test and helps bring about the Heartcatch Orchestra for the first time and the final battle between the Precures and Big Bad Dune) it's played straight.
Konjiki No Gash Bell brings a quite literal example of this trope. Italian Super Star Parco Folgore has a hit song known as "Muteki Folgore" (Invincible Folgore) with the ability to revive him every time he has been knocked down if it is sung by his partner Kanchome.
The first season theme of Hajime No Ippo often plays during Ippo's final drive to victory in a given match.
Subverted in one episode where during Ippo's first match against Japan Featherweight Champion Eiji Date, it is suddenly interrupted by Eiji's counter punch.
The song Inner Light, the opening for that season, begins to play in full Ippo begins his final counterattack against Sendou during the Japanese Featherweight Championship, when he pulls off his newly completed Dempsey Roll for the first time.
When you hear Fate's voice actress, Nana Mizuki, start to sing her insert song for that season of Magical Girl Lyrical Nanoha, expect every villain currently on screen to have their asses handed to them within the next five minutes. Fate gets a particularly big one of these in the form of the awesome "Pray" during the final showdown with Jail Scaglietti and the Numbers.
Similarly, Nanoha gets an awesome variation during her fight with Quattro. As Nanoha's Area Search finds Quattro, the background music shifts from Quattro's synth-organ Leitmotif to Nanoha's "Ace of Aces" battle theme
The aptly named "Shooting time" signals when a hero gets up, sometimes after a memory or speech, and lays the smackdown on one of the villans, preferably with a Wave Motion Gun.
Likewise, whenever "Meteor" or "Vestige" play in Gundam SEED or Gundam SEED Destiny, expect Kira Yamato to appear and disable the entire opposition without a scratch.
When Cagalli shows up in the Akatsuki to help defend ORB from the ZAFT attack in Destiny and the song "Honoo no Tobira" plays. Basically, the ORB forces go from on the ropes to fighting chance, to winning the day when Kira and Lacus show up
G Gundam had two themes dedicated to Domon's Finishing Moves, "Moegare Toushi" for the Shining Finger and the other "Waga Kokoro, Meikyo Shisui" for just about anything God Gundam did.
Many of the tracks of Eureka Seven are meant just as a theme music power up, be it for the heroes or the villains. Whenever Renton does anything especially awesome, a song insert, "Storywriter" begins playing.
The first opening song, "Days", also lends itself to a Theme Music Power-Up for Renton and Eureka in episode 32.
This was also done by Neon Genesis Evangelion. Whenever EVA-01 is about to kick some ass and tear some unfortunate Angel a new one, either The Beast or The Beast II plays. The Beast II is even used for such moments in the crossover Super Robot Wars games. Also, in the series' original Mind Screw happy ending, when Shinji realizes his whole life doesn't need to revolve around piloting EVA-01 and he can live a happy life without it, two versions of the show's theme "A Cruel Angel's Thesis" are played, a strings version, The Heady Feeling of Freedom, and a piano and guitar version, Good, or Don't Be, in succession.
Rebuild gives Shinji his own Theme Music Power up with Sin From Genesis, a remix of Beast II that plays over his epic beatdown of Zeruel.
The James Bond-ish opening theme tune in Read or Die kicks up at the end of the first episode of the OVA, when Yomiko and Nancy square off against Otto Lilienthal and his transforming glider.
And whenever you hear it fire up during the sequel, strap in tight, because someone's about to kick some major ass.
In part I, the titular character had several "commence recovery and ass-kicking" tunes. "The Raising Fighting Spirit" was the most common, but several were held in reserve for really stand-out occasions. To beat Neji, Naruto had to bust out three of these in a row ("Avenger" followed immediately by "Heavy Violence" followed immediately by "Strong and Strike").
Rock Lee has "Utsukishi Aoi Yajuu" (Beautiful Green Beast), which starts up every time it seems like he is going to win a battle.
Shikamaru has the techno song "Fake" which starts up whenever it turns out things have gone All According To Plan.
In part I, whenever Orochimaru's theme music started playing the other guy was screwed. The normal version meant they were merely scared half to death and weren't going to dare stand up to him; the "fight" version was reserved for horrible Curb Stomping.
Seras Victoria transforms into a Draculina and tears through her enemies as Suilen's beautiful, haunting 'Zakuro' plays in the background.
In Dragon Ball Z, when Cell goads and torments Gohan to transcend his Super Saiyan power, Gohan does exactly that, to a tune called "Demon vs. Demon" (in some translations). A fitting name, considering what Gohan basically becomes in this state. An alternate translation is "Spirit vs. Spirit"; the concepts aren't as different in Japanese as in English, but both translations fit the scene pretty well.
In addition, in the dub of Dragon Ball Z there's a theme that plays for Goku during his first Super Saiyan 3 transformation. This music is also played during the entire Majin Buu saga whenever one of the heroes does something awesome.
On top of that, Vegeta got such an awesome song that when I downloaded it from iTunes, it was the second-best selling Bruce Faulconer song, after the main theme. (March 2009) Oddly enough, it's called "Vegeta Super Saiyan", even though he's not always Super Saiyan when it's playing.
This is because Vegeta transforming to fight #19 was the scene that introduced the song
It should be noted that Trunks previously had two insert songs, one of them used for his first Super Saiyan Transformation against Freeza.
Dragon Ball Kai is no stranger to this, bringing in all kinds of new songs for old characters. In particular, Vegeta gets his own insert song while powering up against Freeza, and Trunks who is definitely no stranger to insert music gets a whole new theme titled "Tatta Hitori no Senshi" for his powerup against Cell, even if it does end up a Curb-Stomp Battle in Cell's favor, it's still a pretty badass song. It should be dually noted that both songs are sang by the person's respective seiyuu.
The Shakugan no Shana cast get one in the climax of the fight against Sabrac in Season 2.
Likewise, whenever L really gets going, his guitar theme music flares up to match.
"Little Busters" fills this role several times in FLCL, usually when it plays during a Naota/Canti gattai.
In Katekyo Hitman Reborn!, there is separate theme music for "Look, someone (usually Tsuna) is no longer failing at life!" and "Oh, by the way, I acquired some new way to kick your butt. SORRY FOR NOT TELLING YOU!" ... as well as everything else, to the extent that it's possible to tell what's going on just by listening to the background music.
To be more precise, the songs are called "Shinuki Time!", "Succession", "Hibari's Theme" and "Tsuna Awakens", respectively.
Both played straight, and played very straight by GaoGaiGar. When Masaaki Endoh shouts "GA-GA-GA GA-GA-GA-GAOGAIGAR!", it's fair warning that Guy's power of raw courage is about to rip you apart. Meanwhile, Mic Sounders the 13th has a couple of songs on Disc P that literally power up any protagonist robot in earshot, restoring their energy and galvanizing their fighting spirit.
Also, there are separate themes for the titular mecha's two big finishers, Hell and Heaven and the Goldion Hammer. Also, the rest of GGG's mecha get an extremely hot-blooded theme of their own when they're about to do some pretty awesome stuff.
The latter is heard most notably when they assault the Contra Fall, and is titled after the entire Mobile Unit: "Strongest Brave Robo Corps". There's also the J-Ark's save-the-day tune "Beautiful Wings Of Light", and the ominous guitar riffs during the opening of the Zonuda battle where it pretty much wipes the floor with GaoGaiGar.
GaoGaiGar FINAL has this in spades, when Chouryujin and Gekiryujin are preparing to fight against their respective Soul Master counterparts the theme Saikyo Yuusha Robo-Gundan plays.
Mic Sounders 13 gets this as well as when he first fights his Soul Master counter part he invokes Disk F playing Let's Final Fusion to attack with a Golden GaoFighGar MADE OF ROCK, when this didn't work he used the London's Tower Bridge to play the Guitar solo from Power of Desire and cracks the enemy's Loud G-Stone
The Pokémon anime usually has one of the openings or upbeat endings accompany a sudden comeback (maybe even a whole battle) or evolution. "Pokémon Symphonic Medley" has been common recently, as there is no full version of the song.
In older seasons, they'd use this awesome electric guitar remix of the Gym theme.
Late in the Japanese version of the Advanced Generation series, Battle Frontier would usually start playing when Ash begins to make a comeback. Late Diamond & Pearl episodes were fond of throwing in Saikou - Everyday! in the same situation.
The dub did this a couple times, as well. In the match against Roark, the English Diamond & Pearl theme played. During a Contest with Dawn's rival Ursula, they played Battle Frontier (replacing the line "It's the Battle Frontier!" with "Let the battle begin!"), and the final DP episode had We Will Carry On! syncing up to the Flint vs Cynthia battle.
In one of two of the most iconic moments in the original series is the SDF-1's assault on the Zentrandi fleet, outnumbered somewhere around a hundred million to one. The music was basically all the previous songs put back to back. Then The Movie came around and presented "Do You Remember Love?" the track that is all but synonymous with the series and is the music for what is quite possibly one of the most awesome moments in Anime ever.
And don't forget about the final episode where Kamjin attacks Macross City... then the show's opening theme song starts to play as the Macross takes off one last time and blows the offender out of the sky with it's main cannon.
Macross Plus featured an interesting variation. The music that powers up is not the fast paced songs but Myung's song, the slow tempo Voices, which she uses to snap Isamu out of Sharon's illusions.
Macross 7 puts this to the limit with The Power of Rock. Literally, listening to Basara's singing causes creatures to regenerate Spiritia, something the villains suck out and causes a person to go comatose. In the Grand Finale, his power up was so awesome that it overrode the Big Bad's effect of draining spiritia and helps recover all his teammates. It also featured a new song that played in no other part of the show, Try Again.
Not true. Try Again had been played at least twice beforehand, first when Basara blasted his song THROUGH A METEOR without damaging it to save Gamlin, and again when they tried (and failed) to defeat a Brainwashed and Crazy Gamlin.
Macross Zero inverted this. The Song of Ruin is not a good thing for people since it involves a somewhat Brainwashed and Crazy version of Sara controlling the Bird Human, a massive thing that promptly began to raise total hell.
Macross Frontier does this a lot, especially episode 7. In episode 14, it's subverted — "Sagittarius 9PM Don't Be Late" plays as Sheryl goes into combat for the first time... only for her to be immediately shot down.
Episode 4 featured "My Boyfriend is a Pilot" (from the original series) over Alto's "final exam" in his dual with Klan Klan. What happens next is an awesome fight sequence with choreography to the music.
In episode 24, it is inverted horrifically for the Frontier fleet, as Ranka sings "Do You Remember Love?" for the Vajra, which proceed to overpower the human forces.
The entirety of episode 25 is pretty much THE defining example of Macross Theme Music Power Ups, combining almost every song in Frontier plus "Do You Remember Love?"
Genesis of Aquarion has a Theme Music Power-Up in nearly every episode (along with the usual subversion with stopping the song when the attack fails), and the last episode gets an awesome, gospel style version of the first theme song.
Umineko No Naku Koro Ni: For the protagonists "worldend_dominator", "Far", and "Dread of the Grave" are all indications that a Crowning Moment of Awesome will happen. For the antagonists it will be "happiness of a marionette", "mirage coordinator", "Golden Smile", or "Moon Rabbit's Dance".
Higurashi No Naku Koro Ni's games have it's own series of Songs, with various remixes of 'Dear You'. The instrumental version, 'Dear You - Destructive' is used during one of most Crowning Moments of Awesome, needless to say, Keiichi dodges bullets.
Princess Tutu. Admittedly, all combat is to ballet music, but you could always kind of tell who exactly was getting the power up.
Eyeshield 21 also has some examples of the "with lyrics" variety. The first appearance of "Be Survivor" comes to mind and, later "Chain of Power."
The Devil May Cryanime has a pretty cool theme song, which plays during the final episode when Dante activates his Devil Trigger to finish off the Big Bad. We don't see the full Devil Trigger and the fight is over in a few seconds, but the music makes the scene an odd combination of anticlimax and Crowning Moment of Awesome.
Once YOU WA SHOCK / Ai Wo Torimodose's battle remix starts playing (or for that matter, the fight alteration of "Super Survivor" or "Tough Boy"), then there's no doubt Kenshiro will bring the ultimate form of pain on the bad guy of the day. Then, after the beat down, they arealready dead.
One aversion however, is Jackal, a powerless dynamite-Spamming mook, who manages to live all through that music. And Ken was just fucking with him all that time anyway... up until Jackal calls upon Devil Rebirth.
Vision of Escaflowne does this sometimes. When the Dance of Curse starts playing expect some serious fighting.
One Piece has "Gomu Gomu no Bazooka!", which often plays when Luffy finishes off the villains.
Each character has their own. If a non-Straw Hat has one, they're joining the crew.
If you hear the instrumental version of "We Are" (The show's first theme song), the whole crew is going to be breaking out the beatdown.
General Rule. If you are watching One Piece and Overtaken plays? Crowning Moment of Pure Awesome in the works. No exceptions.
During the Impel Down Arc, Hannyabal attempted to invoke this by having soldiers play music at the beginning of his fight against Luffy. It didn't take.
And even the understandably silent written Manga made a spoof reference to this. When Usopp reinvented himself as Sogeking, he quickly made up and sung his own little theme tune, which was a joke at the time. Later, he turns up to save the day, and happily sings the theme tune to himself as he shoots at the crucial group of marines. Except the change of circumstances makes readers see the song in a whole new awesome light. It came back later when Usopp "transformed" to fight with Perona.
Basquash!! doesn't show the usual title card or play the theme song at the start of episode seven, with the reason why being revealed at the end. It was being saved for Dan showing Rollingtown, for real this time, how hotblooded basketball is played. The theme song shows him the way.
Nearly any fight in The Third!, most notable One-Woman Wail "Sword Dancer" during first and tension rising "Storm on the Battlefield" during last battle.
Most fights in The Law Of Ueki start the opening theme as the final attack is used, which then continues through the whole opening, even if the fight has already ended.
In the Black Lagoon anime, various rock songs inevitably start up whenever awesomeness is about to come down. The most notable is the song "Peach Headz Addiction", which only plays when Revy lapses into Whitman Fever.
In the final episode of Ouran High School Host Club the ending theme starts early as Haruhi goes after Tamaki on the carriage on her own, even using the soft guitar opening to the song which signals the end of the episode to tease a Downer Ending, and the episode had a special ending to avoid repeating.
Whenever Athena's Saints in Saint Seiya mustered their courage and burned theirCosmo beyond its limits, they'd receive either a full-on brass fanfare or a gorgeous orchestral arrangement of "Pegasus Fantasy". Asskicking of Olympian proportions would ensue.
In Gaiking, should you happen to be hearing the sound of trumpets - it means Daiya is about to kick ass.
Transformers Victory's opening theme music plays whenever Star Saber does something particularly awesome. Road Caesar and Landcross each have their own remixed version.
Keroro Gunso example. In episode 103, just as the Garuru platoon has utterly defeated the Keroro platoon, Natsumi is down and Keroro himself has been transformed into a psycopathic frogchild version of himself, Fuyuki snaps him out of it...cue the first opening theme as Keroro rallies the troops. 3! 2! 1! FIRE!
Played straight in recent a recent chapter as Soul can make a keyboard out of his arm and play whatver music will make a person go insane.
In the MazinkaiserOVAs, whenever Kouji lays the pain down his opponents, the song Mazinkaiser's Theme starts playing, though it's the short version. In the final episode, "Decisive Battle! Burning Hell Castle", the full version of it is played the moment Mazinkaiser unleashes Kaiser Blade and doesn't stop until he delivers the final blow onto Hell King Gorgon.
Shin Mazinger manages to pack three one after the other in the final episode, as the second opening, second ending, and finally first ending play in sequence over the final battle.
Tekkaman Blade: When Blade receives his Blastor power up, Eternally Loneliness starts playing. Blade proceeds to send Lance running with his tail between his legs, before blowing him up with a souped up Voltekka. The same Lance that spent the better part of episode bragging about how he was superior in every way.
00 Gundam from Mobile Suit Gundam 00 initially failed to reach optimal operating conditions in light of an impending attack on the Gundam Meister's ship (Season 2, Episode 2). 00 Gundam gets its own semi-acoustic version of the soundtrack by the same name as Setsuna activates Trans-Am, thereby forcing the Gundam to reach a stable operating state. This results in all parties present pausing to admire the flash of emerald light and marvel at the Twin Drive system. The music starts up in earnest and 00 Gundam proceeds to rape the attacking "Ahead" mechs.
Also in season two, "Trans-Am Raiser", and the movie had "FINAL MISSION! QUANTUM BURST!" Whenever those two start playing, lots of stuff blows up at a constantly increasing rate.
Cowboy Bebop. In the final episode as Spike goes on a rampage against Vicious and his former crime syndicate, the next five minutes of awesome are shown with See You Space Cowboy, an arrangement of The Real Folk Blues, playing in the background. Crowning Music of Awesome with saxophone and piano!
In SD Gundam Force episode 52, the 3rd opening theme Taiyou Ni Kougarate plays when the heroes begin their ultimate attack on the Big Bad
Also, in just about every episode, the battle is resolved by the kid getting excited, which activates the Soul Drive, which starts the trumpet solo, which gives the Gundams the power they need to save the day.
The second anime of Fullmetal Alchemist has the fight against Sloth, where Olivier Armstrong is cornered and her brother gloriously saves her with his supreme manliness complete with an epic theme song that could only be described as the armstrong national anthem. The exact same thing happens a few moments later when Izumi's husband and aforementioned brother meet for the first time. Starts around 3:00 in this video.
Shaman King poses a subversion in the final fight, where all main characters are fighting the villain Hao/Zeke, and the main theme starts playing. Everyone is sure Hao is going to get his powered-up rear kicked, when the song suddenly stops and the tide is turned, changing the song to Hao's fighting theme
To Aru Majutsu no Index has "Jellyfish" by Mami Kawada. This plays when Index is alone and Sherry Cromwell's Golem attacks her. Index then goes on to show that even in her normal mode she is able to call upon the power of the 103,000 grimores she has memorized and easily repels the Golem's attacks until Touma comes along and cancels the whole summoning.
Also at the end when they defeat Telestina and save Kiyama-sensei's kids. The same Saten-san who needed the pep talk before became the big hero by delivering a Shut Up, Hannibal! to Telestina and smashing the CapacityDown with her baseball bat.
And now with Mizuno leaving, TMPU has fallen to the east maiden Keito.
In The World God Only Knows, the opening theme plays when Keima goes into God of Conquest mode in episode 12 of Season 1.
The final battle (against The Rival Papillion) in Busou Renkin is accompanied by the title theme. It is, like their first fight, fast paced and impressively choreographed, even if it is more down to earth than the fights involving gravity manipulation and Humongous Mecha.
In Nerima Daikon Brothers, the titular band often sings a revised version of their theme song with lyrics adjust for the villain whose butt they're about to kick. It's basically a show rule that if the theme song's not playing, they're not about to win.
The Meaning Of Truth, the theme of the F-Zero anime, starts up during that famous scene at the end, where Captain Falcon jumps out of his Blue Falcon and FALCON PUNCHES Black Shadow to his death.
In Rental Magica, when Itsuki removes his eye-patch, the music starts, and he says a variant of, "This is an order from the President!" asskicking will commence. Except that one time in the last chronological episode, where he abused it just to get them to listen.
When Fairy Tail's Dragon Slayer theme starts playing, expect much ass kicking and property damage to ensue. This theme tends to be reserved for the seriously close fights; for more standard epic beatdowns, they use Natsu's main fighting theme.
Rurouni Kenshin has an unusual example of this trope. Kenshin's personal kick-ass music is an acoustic guitar theme that plays whenever he does something badass. Which is fitting considering the character.
Irresponsible Captain Tylor likes to play with this. Whenever Straight Man Lieutenant Yamamoto tries to do something awesome and profound, his theme-tune starts up - a militaristic, Music to Invade Poland to-ish piece that brings to mind Toshiro Mifune's samurai-era masterpieces. Only for it to, inevitably, be interuptet by Tylor's easygoing comedy-movie-style theme when Tylor interrupts his badassery with something utterly stupid that nonetheless somehow manages to save the day. He even manages to throw down the occasional Record Needle Scratch, usually followed by a few seconds of complete silence while everybody in the area stares at him in gobsmacked disbelief.
Gunbuster plays it straight when the Buster Machine rises from Exelion while the Gunbuster March plays. And then, in Diebusterthis is played with when Nono begins singing the original show's theme song prior to her transformation sequence, subverted when the space monster erupts from Titan and the Gunbuster March begins playing prior to changing to a more sinister theme, and finally played completely straight when the real Gunbuster March plays as Buster Machine 7 warps in to save the day.
We get a very literal example in Senki Zesshou Symphogear in which Symphogears are actually activated by the girls singing their theme songs.
In Fooly Cooly (or Furi Kuri or FLCL) Little Busters plays every time Nao merges with Canti, becoming Atomsk, and most other times Atomsk appears to save the day.
The Expendables has "Diamond Eyes" playing in the climax of the film. The eponymous team charges into the courtyard, shooting and tossing hand grenades left and right.
Subverted twice in a very short time in the Lord of the Rings film Return of the King. After the Riders of Rohan and Gondor coalition forces have routed the orc forces, and the king has shouted "Make safe the city!", the triumphant music abruptly fades away as the audience hears what sounds like a distant rumble of thunder, and swiftly turns includes the bellows of the towering Műmakil war-elephants-on-steroids and the warchants of their riders, the Maori-reminiscent Haradim.
However, the music returns as a counter charge is ordered, and the cavalry make yet another music-backed charge to the line of Műmakil...only for the music to be cut off as if someone pulled the plug from the sound system, or if the orchestra themselves had fled the battlefield upon realizing what a terrible idea charging fifty foot elephants with horses was. Incidentally, the music is cut off at the exact moment that one of the warbeasts swings its tusks, sending a horseman screaming into the air, then smashing more aside with its feet. It takes another few minutes (film-time) before anything resembling victory seems possible...and then the Nazgul, including the Witch-King, show up.
Played straight a little earlier; when Aragorn grasps hold of Andúril for the first time, his personal theme music swiftly switches from a bouncy Fellowship-based ditty to a roaring orchestral King of Gondor crescendo.
In the Spider-Man films, Spidey's action scenes are usually accompanied by his distinctive leitmotif. The villains also get their own theme music. In climax of the third one, Spider-Man's theme gets very noticeably cut off whenever the villains get the upper hand.
"Holding Out for a Hero" in Short Circuit 2; for those too young to remember that one, it was also in Shrek 2. With full orchestra support from Harry Gregson-Williams in the latter case.
At the end of the Mission Impossible movie.
Even better in the second one, when the hero is dead and the villain victorious (complete with his own music rising to climax), only to change abruptly to the hero theme as we see that he (and we) have been deceived.
Right towards the end of the 'The Matrix'', when Neo becomes The One, and is seeing the "code" for the first time. One-handed kickassery follows.
Most people will never be able to hear The Propellerheads' "Spybreak!" without thinking of the lobby shootout scene again.
The Rocky movies are no doubt well-known for their sudden comebacks, almost always accompanied by one of Rocky's many theme tunes. Usually, just as the finishing blows are made, the music builds to a dramatic climax. This is no more evident than in the fifth movie (otherwise not worth the time) where, as Rocky lies concussed in the streets during a brawl with Tommy Gunn, he goes into an almighty hallucination, remembering his dead trainer Mickey before finally snapping out of it as Mickey screams at him "Get up, you son if a bitch... 'cause Mickey loves ya." The music swells as Rocky rises again... then it suddenly bursts into a weird ghetto remix.
Parodied in Kung Pow! Enter the Fist, where one of Master Betty's minions plays music on his boom box, to which tune Betty pummels his victim.
"By the way, you must beware of Betty's iron claw. They are sharp, and they hurt. And beware his song about big butts, he beats people up while he plays it!"
And in the final showdown, the Chosen One throws a shuriken at the boom-box, causing it to start playing the Ram Jam version of (probably) Huddie "Lead Belly" Ledbetter's "Black Betty".
Sometimes done just before a scene's climax, when the heroes have the upper hand and the enemy hasn't made his final play yet — such as in the Scooby Doo movie, where a remix of the classic theme plays for a while before the gang really winds up in trouble.
"Secret Agent Man" playing in the final battle of the first Austin Powers movie may qualify; again, it dies down before Austin's final confrontation with Doctor Evil.
At the end of Pirates of the Caribbean: Dead Man's Chest, Jack Sparrow's confrontation against the kraken is made even more awesome by the remix of He's A Pirate that plays during it.
And then abruptly turns tragic as the heroic strings drop into a dying fall... just as the Black Pearl is pulled beneath the waves.
Probably averted in the first Pirates of the Caribbean film. Jack Sparrow's first scene in the film is standing on the mast of his sinking ship, and yet the music that scores this scene is unabashedly heroic (and serious to the point of self-parody).
Unaverted in Pirates of the Caribbean:At World's End, when Jack Sparrow comes over the sand dunes in Davy Jones' Locker in a reference to his first entrance.
Also, of course, there is a general rule in all Star Wars films that if you can hear Imperial March, it means The Dragon is being awesome again.
Even detractors of the Star Wars prequels admit that one of the coolest moments in the series was near the climax of The Phantom Menace when just as the heroes are ready to flee the scene, a door opens, a cloaked figure appears (Darth Maul), and the first few notes of the "Duel of the Fates" theme are heard.
In the original film, the power up music comes at an interesting moment: when Luke shuts off his targeting device the score shifts from tense to triumphant. It means he's decided to trust the Force and is on the path to becoming a Jedi. Actually blowing up the Death Star is just a detail.
Mr. Mistoffelees on the filmed version of Cats. His song, though enjoyable, is so odd and repetitive and full of praise that it seems he's doing the song mostly to get the crowd to believe in his powers so he can actually do anything.
However, since the song is actually performed by Rum Tum Tugger, it could be argued that Tugger is actually trying to convince Mistoffelees that he can do the magic that needs to be done.
When it's time for a dogfight, what's the first thing the hero does in Iron Eagle? Put some rock into his tape deck, of course.
Why the Superman wasn't added a long time ago is beyond me. It is the sound of powering up.
Later used/homaged in a climactic moment of I'm a Marvel... And I'm a DC's "After Hours" storyline. The circumstances did it justice. Which is to say, it was appropriately awesome.
In Godzilla Final Wars, Godzilla's new theme "King of the Monsters" kicks in just as he blasts off one of Keizer Ghidorah's heads after being revived by Ozaki in the Gotengo. Godzilla then proceeds to utterly destroy Ghidorah by tossing him into the air and blasting him with a spiral beam.
A possible subversion or inversion could be the laughably quick death that the American Zilla receives from the true Godzilla while the English (but not American) song "We're All to Blame" plays over its fight.
In Galaxy Quest, at the end of the movie, the real Protector, with the cast members on it, crash-lands at a Galaxy Quest convention. The film's Big Bad, Serris, is still alive — until he's shot, in full view of the entire convention audience, by "Commander Peter Quincy Taggart". The film's triumphant theme music plays. It's over. However, in the beginning of the movie, the guy was a pure egotist, basking in the spotlight at appearances and so on. Now, he's learned his lesson, and he invites the crew up to take a bow. When this happens, the music switches to a higher, remixed triumphant version with plenty of choir — the Commander's won the real battle. The movie ends there.
Iron Man had great fun with this, playing the driving guitars of the hero's theme and then stopping the music abruptly when circumstances changed. Best example would be our hero taking out a group of terrorists and flying along with music blaring until he takes a tank round to the face and crashes. He stands up, fires with disdain a tiny little rocket, and turns around to walk away. Looking back, we see the tank explode dramatically and the music picks up right where it left off.
And the literal powering up scene. Stark has decided enough is Enough and decides to go to settle the situation in Gulmira, personally. As Stark stands in the middle of his workshop the floor opens up and numerous robot arms apply his Mark III armor, now with iconic red and gold scheme. The track that plays is appropriately titled "Iron Man", on the soundtrack by Ramin Djawadi.
Similar moment, although with a different soundtrack, in Iron Man 2, accompanying the racetrack fight.
Two moments from Star Trek: First Contact spring to mind: the battle against the Borg cube at the start of the movie, where the Enterpriseswoops to the rescue to the sound of an absolutely epicfanfare, and the fight on the deflector dish, where each time the Borg gain the upper hand, a more thunderous version of their Leitmotifplays.
In The Wrath of Khan, we get three power-ups: Once when the Enterprise leaves its dock, one for Khan during his surprise attack, and again for the Enterprise during the Lock and Load Montage.
Pretty blatant in the climactic fight scene of Only the Strong, a 90's action film about capoeira (a Brazilian martial art): the main character is about to be killed by the Big Bad, when all of a sudden the main character's students (who are watching the fight, along with the Big Bad's minions) start singing the capoeira song he had taught them earlier in the film. This gives our hero the energy boost needed to fend off his opponent, then royally kick his ass.
Whenever Optimus Prime enters the big ending battle in both movies, the music soars as Prime either epically transforms or gets new armor, weapons and flight capability donated from the deceased Jetfire. Both complete with a one-liner to emphasize that yes, this is awesome.
Happens subtly in Star Trek. If you hear a snippet of the main riff from "Enterprising Young Men", ass-kicking will soon ensue. Especially egregious when Sulu gets dangerous.
In Halloween 2007 (2007), Michael gets better from his sister stabbing him through the shoulder and recovers his discarded mask when his "stalking" theme starts up.
In Beverly Hills Ninja, there is a fight with the obligatory Kung Fu Fighting by Carl Douglas. When the fight gets more intense, it hilariously speeds up.
The Man Who Saves the World is really shameless about this. Every single time the hero starts winning a fight, his music starts playing. The real kicker is that his music is just the Indiana Jones theme.
Once Upon a Time in the West Sergio Leone is pretty good at this, especially in OUATITW, where Charles Bronson has one of the best themes ever associated with a movie protagonist. The spooky sound of the hamonica accompanies his raging revenge through the movie, and every time you hear it you know that he'll do something awesome.
When watching the original 1989 Batman, the minute you hear any version of Danny Elfman's classic Batman theme, there's gonna be some kicked ass. No questions asked.
This applies to Batman Returns as well.
This also happens in the Nolan films. Zimmer's Batman anthem is maybe less memorable than Elfman's, but it's always there when Batman kicks serious ass (listen to the score in the "Swarm of Bats" scene from Batman Begins).
In Gladiator, General Maximus has a driving, forceful orchestral battle theme only heard twice, once on the German battlefield and once in the Colosseum. In both moments he is leading armies to victory like a true frontline general.
The music in Thor kicks into high gear when the eponymous hero's powers are restored at the end and he proceeds to kick major ass.
Blatant in Jimmy Neutron: The Movie - whenever he starts implementing a new plan, or is in the middle of using ANY invention for WHATEVER reason, a variation on his theme tune starts playing. Yes, even when he's just getting ready for school. Either that, or some new-wave, boppy, pop song comes on (as evidenced during the defeat of the Yolkians in the arena).
The ending of the original Dawn of the Dead. The main guy is trapped in a room with a hoard of zombies about to come in. He gets ready to kill himself, but he suddenly turns the gun around and shoots a zombie instead. Cue the cheesiest patriotic fanfare you can think of as he pushes zombies out of his way and runs to escape with the main girl. It's a good thing that music came out of nowhere and made the zombies completely ineffectual, or it would have really been a Downer Ending, which is actually what the original script called for.
Kick-Ass, Hit-Girl and Bad Reputation; exactly as it says in the title ensues.
Invoked in The Avengers: When Iron Man arrives on the scene, he hacks the nearest speaker system (which happens to be Black Widow's jet) to play AC/DC.
Later on in the film, we hear a triumphant version of the film's main theme once the Avengers finally assemble as a team for the first time during the climax in New York.
Numerous examples in Power Rangers in all of its incarnations. For example, after Tommy lost his Green Ranger powers in the first season, yet proceeded to fight off Goldar anyway (to the tune of "Go Green Ranger Go").
Theme Music Power Up is the only context where we get to hear the original Power Ranger theme with lyrics in its verses. ("No one will ever take them down / The power lies on their si~i~i~i~i~ide! / Go, go, Power Rangers...") Giving a previously instrumental theme some lyrics, when done right, seems to give a power-up to the theme music.
Particularly, in the crossover episodes, the visiting team gets the theme music for the previous season when they escalate. In Operation Overdrive's "Once a Ranger", we're treated to five earlier incarnations of the theme music, cleverly mixing together (Well, four; for some presumably legal reason, Adam gets a new theme song rather than the original "Go, Go Power Rangers" theme.).
Jasmine: Please excuse me. (place hand on Ryouga's hand) Narrator:(while clipshow of Abaranger goes on) Jasmine is an ESPer. Whoever she touches, Jasmine recaps his memories. Jasmine: Seems true for now. I have my doubts for them though — (walks to the camera) — Aba-Aba-Aba-Aba-Abaranger! Umeko: What the heck was that? Jasmine: Don't know either. It was on loop in his brain.
Kaizoku Sentai Gokaiger takes this concept and runs with it. As an anniversary series for the franchise, the Gokaigers not only get a Theme Music Power-Up from their own theme, but the theme music of whatever past sentai team is getting spotlighted that episode.
Has been lovingly taken up by Top Gear, who have used it repeatedly when doing something particularly A-Team-y to their vehicles. Has gotten to the point that Clarkson sequed into an A-Team Montage by saying, "And then it was time to cue the music ..."
Kamen Rider Den-O has a different version of "Double-Action" for each of Ryotaro's five forms. Ryuutaros, however, takes it a step further. He gets a hip-hop remix of the show's Theme Song and the above mentioned "Double-Action", that play almost every time he shows up. This includes when he's stalking rival Sakurai Yuuto. Speaking of, Yuuto and his partner Deneb get their own theme music, called Action-ZERO.
Though it doesn't quite fit under a category, when one of the Riders in Kamen Rider SPIRITS is about to have a nice big one-against-all-of-his-monsters-of-the-week-ever battles, the lyrics to an appropriate theme song are written out on the page (V3's sequence is notably impressive).
Especially powerful in Kamen Rider BLACK's final episode when Kotaro powers up with Long Long Ago 20th Century in the background to fight his brother, Shadow Moon one last time.
"W-B-X ~W-Boiled Extreme~", the theme song for Kamen Rider Double, plays exactly three times during the series: during the fight where the Riders finally get the upper hand on the Weather Dopant, in the penultimate episode when Shotaro faces off against the Utopia Dopantwithout transforming into Double, and at the end of the final episode when Shotaro and Phillip become Double for the first time in a year and defeat the Energy Dopant. It also gets played in The Movie during the final battle with Kamen Rider Eternal, specifically when Double gets his Eleventh Hour Superpower and Rider Kicks Eternal into the stratosphere.
Doctor Who never uses the main title theme itself in the scores to the episodes. However, in the new era:
The Doctor had "The Doctor's Theme" in Seasons 1 and 2 supplemented by "All the Strange, Strange Creatures" in Season 3 as his theme, with the latter playing whenever it was time for action. The Doctor's Theme comes back all powered up for season 4, with an instrumental in "Forest of the Dead" and orchestration in "The Stolen Earth. Then, in the finale of the Tenth Doctor (and of Russell T Davies as showrunner), the two themes were combined to score the Doctor flying to the mansion and dropping down onto the Master. And finally, to overscore the Doctor's regeneration, they power it up one last time. The Eleventh Doctor has a new theme, which gets louder and stronger for special occasions.
The Daleks' Hebrewchoral theme becomes twice as powerful in "The Dark and Endless Dalek Night," and an echo of it is heard in the introduction of the New Dalek Paradigm.
Rose's theme is powered up when she is superpowered by the Tardis.
Martha's theme becomes "Martha Triumphant."
Donna's bouncy theme becomes more complex when she reunites with the Doctor.
Meanwhile in the classic era: A key element of the title theme was used as the climax to Tom Baker regenerating into Peter Davison, making the Doctor's death and renewal both poignant and triumphant. When the scene was repeated as the teaser to Davison's first story, the title theme element in the music cue fed straight into the opening titles themselves.
Airwolf, a lot, including literal cases, where the theme tune plays as Airwolf starts up, and goes full-blast during the climactic fight scenes. In fact, you can usually predict down to the second when the final explosion will take place as it will be in time with the climax of the theme.
On Heroes a ticking clock sound starts playing whenever Sylar gets up to his serial killer shenanigans. It fits his backstory as a watch repairman, and is damn creepy to boot.
In the Season 3 episode "I am Become Death", this trope is played around with when Sylar's theme is played again for another character, Peter, as he loses control while trying to use Sylar's power. It's creepy and effective.
Batman usually fought goons to the sound of his theme music. And it was AWESOME.
Doubly awesome as every BIFF and POW is accented by a musical sting.
Spaced spoofs by powering with another show's theme: Mike gets brooding Mad Artist Brian to go from mouse to man by playing the Thunderbirds theme.
Buffy the Vampire Slayer did this in its first-season finale "Prophecy Girl," playing the show's theme (performed by Nerf Herder) during the climactic fight - the only use of that arrangement of the theme music within an episode.
In an example of the character playing their own theme song, basically any time Omar Little of The Wire whistles "The Farmer in the Dell," odds are he's about to add yet another act of pure badassery to his resume.
Everytime Grover transforms into Super Grover in Sesame Street (He gets a version with Rock Guitar in Elmo Loves You)
Oddly enough, even a network can be powered up through theme music. Remember "HBO in Space", the ident to new movies HBO used in the 80s and 90s?
"This intro makes me feel like I am about to witness the most important event in the universe." -sterpinator, YouTube commenter
This happens twice in a single episode of the reimagined Battlestar Galactica. In "Exodus Part 2", during the escape from New Caprica some fairly standard, percussion-heavy music is playing, until the Galactica shows up falling from the upper atmosphere, launches vipers, and jumps away at the last second, all of which is set to the most triumphant bagpipes you can imagine. Later, as Galactica is getting pounded by four Cylon basestars and everyone has given up hope, the music is slow and somber. The camera pans out until a missile appears from off screen, and then another one, until the camera turns around to reveal the Pegasus in the nick of time and the music the music goes back to the exciting drum music.
The pilot episode of Firefly features dueling theme music during the aerial chase between Serenity and the Reaver ship, with the Reaver's theme growing louder and more ominous the closer they get - only to be blown away by Serenity's theme when the ship pulls its Crazy Ivan maneuver and leaves them in the dust.
The season 2 finale of Teen Wolf uses the season's opening credits theme in the climactic fight against Grandpa Argent.
Smallville brings the series to life for a last time, delivering Superman's original theme from the movies when Clark is throwing away his glasses and opening his shirt to reveal the "S" symbol on the last scene of the series. The last redeeming moment in 10 years.
This happens many times in the videogame "Lollipop Chainsaw" where you're on a combine in one level mowing down zombies while "You Spin Me Round (Like A Record) by "Dead or Alive" or when you activate your Sparkle Invincibility and you hear "Hey Mickey" by "B*Witched" while you are invincible and kill enemies effortlessly.
In the Gamecube version of Soul Calibur 2, Link's theme starts blaring as he begins his destined battle against Raphael. Hearing the tune really pumps you up to kick Raph's arse.
Samus does have her own theme music by this point in the series, which plays over her revival (both times) in Metroid Prime 3: Corruption and over Super Metroid's opening text crawl and end credits. It also gets an orchestral remix in Super Smash Bros Brawl.
Speaking of Metroid... Late in Metroid Zero Mission, Samus is stripped of her armor, and is forced to retreat from a pack of murderous space pirates who can kill her in one shot. She gets two consecutive Theme Music Power Up moments:
Samus then retaliates against the pirates with a vengeance, now able to destroy them in one shot, with an up tempo version of the Brinstar theme song blaring all the while.
The final boss of Metroid Prime is accompanied by the already slightly creepy, Ominous Latin Chanting filled main menu music, warped to sound even stranger and more alien. Given that the main menu has the interior of a metroid for its backdrop, this really drives home just how wrong the final boss is, even compared to life energy sucking floating fanged jellyfish.
Both Ridley and Dark Samus have Evil Theme Music Power Ups in Metroid Prime 3: Corruption. In the case of Dark Samus, it's a Big Damn Villain moment too.
Metal Gear Solid 3 invokes the song Snake Eater if the player is running out of time in the final battle with The Boss.
Metal Gear Solid 4 plays with this, where playing certain songs on the I Pod provides ingame bonuses. Naturally the ridiculously awesome Metal Gear Solid 3 theme (Someday, you walk through the raaaaaaain, some day you'll feed on a treeeee frog!) makes you almost unstoppable.
Then there's the finale of MGS4, where a final fistfight with Liquid Ocelot comes in four parts, with theme music from each main game of the series (and matching health bars) for each section, until the music runs out of steam and it's just two old men throwing their last ounces of strength at each other.
Zero in the Mega Man X games has a different theme song in every game, and it always plays when he does something awesome (blowing off Vile's mech's arm in the first game, sacrificing himself, destroying a copy of himself in just three shots, etc.).
This holds true in the Mega Man Zero saga. Whenever that particular game's Zero theme song starts sounding, rest assured — you're about to do something very cool.
Also, the music changes into the foreboding final stage theme after the first form of the final boss is defeated and the Ragnarok satellite is plummeting toward the planet with Weil making a last bid by hooking up to the remains of its control system and directing it towards Area Zero. Then Zero has his "World of Cardboard" Speech and the absolutely awesome final boss music starts up.
And Mega Man Battle Network games have a theme in each game, based around the same two tunes throughout the series, which is played for no other reason other than to show off how something heroic is going on.
In what can only be described as Mood Whiplash, the 6th game has a slow, sad version of the theme, as Iris and Colonel reveal that they are going to fuse, deleting them to get rid of the Cybeast inside the titular character, then "You're Not Alone" plays as the event actually happens.
The Mega Man NT Warrior anime even did this in the Japanese version — if you heard the theme song, it was time for the heroes to start winning. Without fail. The dub did not retain this tradition.
The final match of the N-1 Grand Prix was, of course, between Netto and Rockman and Enzan and Blues. The fight takes place while the Anime Theme Song, "Kaze wo Tsukinukete", blares in the background, and both Navis pull off the Program Advance Beta Sword and commence a swordfight so epic the holographic display almost can't contain it. And then Blues wins by way of Single Stroke Battle. Rock falls over, and Blues and Netto both congratulate Rock on his hard fight while a slow, sad ballad version of the very same opening theme plays.
In Mega Man ZX, you get a brief moment of your protagonist's bright idealism, accompanied by Green Grass Gradation (the very upbeat and optimistic Area A music from the very beginning of the game), before commencing the final battle.
During the second fight with Dracula in Super Castlevania 4, the music changes from the level music to Simon Belmont's theme. Note that this has worked in reverse as well; Dracula's theme music, Dance of Illusions, usually plays in the fights where he's the most difficult to defeat (like in Dracula XX, where the battle takes place over a series of bottomless pits).
Two examples of this one in Castlevania: Aria of Sorrow. In the first example, when you enter the boss room for The Arena, the normal boss music plays, as a cloud of bats flies outward and reforms into one Giant Bat. Then, a giant hand stretches out from the background (a huge shattered cage) and crushes the bat in its grip, just as the music changes to an entirely new boss theme. You end up fighting Balore (a giant ogre), one of the tougher bosses in the game. The second example is in the extended ending. If you fight the normal final boss, Graham, a certain way, you will inherit Dracula's powers once you defeat him. This allows you access to a previously sealed area of the castle... where you get to fight Julius Belmont himself! The battle is a tough one, too — especially because Julius has the best theme music in the game.
This is essentially the effect of Star Power in the Guitar Hero games. Once activated, every note you successfully hit earns you double points, and the crowd rhythmically claps in unison. This is a great way to save you from certain death on difficult songs like "Bark at the Moon" and the faster second half of "Hangar 18".
Used throughout the Halo series. The Halo Theme generally starts playing whenever things get particularly exciting — a narrow, timed escape, a huge, 3-way battle, etc. And, of course, whenever Master Chief does something utterly awesome, the theme WILL be playing.
Depending on how awesome whatever Master Chief is doing is, you might get the "Brothers in Arms" mix, the "Rock Anthem / Mjolnir Mix," or the "Covenant Dance" mix.
The best example being the final mission of Halo 3, which consists of one of the most epic escape sequences in video game history.
The Arbiter actually gets a mix of his own as well: "Unyielding," introduced in Halo 2, which plays when riding into battle against the Brutes in the last few levels. This track is later spliced into the Halo 3 version ("One Final Effort") that plays during the big escape at the end.
How has the "Breaking Benjamin Room" of Halo 2's Gravemind mission not been mentioned? Towards the end of the level, the player must go through a room full of combatants from both the Elite and Brute factions in a firefight. Breaking Benjamin's "Blow Me Away" plays through here, and the rock quite fits the awesome battle the player is about to participate in.
In Halo 3: ODST, expect varients of the Menagerie or Orbital Drop Shock Trooper to kick in whenever something awesome happens. And of course, Halo: Reach continues the tradition with variants of Unreconcialed, Lone Wolf, or Noble Mission kicking in whenever Noble Team readies up for asskicking.
Each area in Phantasy Star Online has two songs (or parts if you see the song listing in the Sound Test or the OST). Part one is soft and calm while part two, which starts up when enemies attack, is more intense and has a harder beat to it. Both parts last almost the same length and have the same BPM, which lets the BG music flow from one song to another as if it were just the same song just getting more intenser. The intensity between the parts goes up with each episode as well.
Sonic the Hedgehog 2 did it best with the Super Sonic theme - music that tells you immediately that all bets are off.
With the Adventure series giving each playable character theme song, said theme tunes were often used as leitmotifs, which ended up having this effect at times. Take, for example, Sonic Adventure 2. Dr Eggman's Egg Golem. In the Dark Story, Eggman moves to strike Sonic, to his own theme music. Then Sonic's theme tune suddenly takes over. Sonic dodges the attack, jumps on the Golem's head, and - with a TERIAAAAA! - delivers a single flying kick to the mind-control device on the Golem's back, which destroys it and sends it attacking Eggman instead.
Sonic Generations used several times in Sonic Generations. In the Shadow rival battle, the stage's music gets replaced by Live and Learn or All Hail Shadow, when Sonic or Shadow (respectively) gain full power of the power-up they're chasing.
Another time is during the Time Eater boss fight, using the Super Sonic theme from Sonic the Hedgehog 4 mixed into the soundtrack. Does it first in the cutscene at the start when both Sonics turn super, and again for the last hit on the boss.
Inverted in Final Fantasy VII: A Flash Back to the Big Bad's deteriorating mental state is accompanied by a few, looping malevolent chords. When he snaps, they extend and turn out to be the opening of his leitmotif.
"One Winged Angel" is used several times through the VII Compilation as a Theme Music Power Up, most notably the above-listed transformation into Safer Sephiroth, as well as the fact that the song pretty much brought Sephiroth back from the dead.
In Crisis Core, there's a cutscene showing Sephiroth, Genesis and Angeal having some fun on top of a virtual version of the Junon Cannon. When Genesis gets a little too serious about the fight, a version of "One Winged Angel" kicks in to show that Sephiroth is no longer playing around.
When the main plot of Chrono Trigger starts up, they even let you bask in the theme music during enemy encounters.
Also, characters' personal themes. Frog is particularly notable for this.
Magus has a theme song that's awesome enough when your party is fighting him. However, if you happen to have him in your party when fighting the Bonus Boss, his mother, he personally taunts his enemy and replaces the normal boss song with his own.
When Dalton commandeers the Epoch, he complains about the heroic music (which is in fact the main protagonist's theme) that starts as it engages ("No, no, no, no...! Stop the music!") and replaces it with a more villainous tune. ("Ha! There we go!")
In the Advance Wars 2/DS/Days of Ruin, when a CO Power is used, the normal CO theme will be replaced by a heavy metal tune depending on the CO's faction.
Some of the effects last until the next day/turn however, even though the theme is replaced by your respective enemy theme during their turns. Weather effects caused by CO powers can even last up to 3 days.
Also happens when Will/Ed appears in the middle of Hope Rising to save everyone from Greyfield/Sigismundo. His normal theme plays, yet before he arrives, you have no CO, so you have the no CO theme until he rolls up.
An observed property of the upcoming game Fable II is that the more rhythmically you kick ass, the more awesome the BGM becomes.
Super Robot Wars uses this by default. The music that plays during any unit's Attack animation is often it's series theme song. Same for the non-Badass Normal characters in the Original Generation games, until the remake gave everybody their own. In all SRW games, they will also play the trope completely straight at appropriate moments in the plot, and will play an entire game's theme song when some serious beatdown is about to commence. Through the Alpha and OG series', Elzam Branstein's "Trombe!" is so Bad Ass, overrides almost all other theme music (even bosses), and results in much ass-kicking. Particularly from Alpha 3 onwards, there is the option to change the unit's battle music, with exceptions (such as "Goldion Hammer" and "Goldion Crusher", which only play during their attacks — their Bad Ass attacks). In addition, the Sound Force from Macross 7 literally defeat enemies by singing at them — and can also power up your other units with their music.
Though, of course, that was rather the point of Sound Force. Up to and including powering the Wave Motion Gun of the show by the end.
The spin-off game Endless Frontier also uses this liberally: while the normal battle themes are randomly selected from 4 different possibilities depending on who's in the party, the character-specific theme starts playing whenever someone uses one of their special attacks.
SRW manages to take this to a true extreme in Alpha 3 when a song composed as a collaboration between Minmay and Basara (in the story, at least) actually saves the day in the final stage, by galvanizing the heroes against a wave of malice that comes from the series' ultimate Big Bad. It's no coincidence that the song was created in Real Life by JAM Project for that game.
Sorry, I can't hear you over the sound of how TROMBE! I am.
Interesting to note, "Trombe!" was not the first instance of theme song override in the series. In Alpha Gaiden at least, certain units had "super attacks" that would trigger a different song. "Satellite Cannon", "Riders In the Skies" and "Dark History" were not programmed to have a lower priority than boss songs.
Sheryl, in Scenario 18-A of Super Robot Wars Z 2: Hakai Hen, sings "Iteza Go Go Kuji Don't Be Late" to pump up the heroes so much that they all instantly shoot to 130 Will and beat the Beastmen mooks. Baron Ashura arrives with some Kikaijuu, so Ranka takes the stage and sings her song "What 'Bout My Star?". Simon and Kamina get pumped up even further, to the point that Kamina debuts Gurren Lagann's famous Giga Drill Break(er), nearly obliterating the Kikaijuu Taros D-7 with it
And, in the spirit of SRW, Battle Moon Wars does the same thing. Villains will always override songs with their own themes when they are engaged, and several characters have their multiple themes. For example, Shirou's default music is the one used for Fate/stay night characters, but when using Nine Lives Blade Works, it changes into a remix of Emiya.
Speaking of song overridings, Dynasty Warriors have Lu Bu, which Elzam seems to be an Expy of. And finally, in Samurai Warriors, there's Honda Tadakatsu for the man of theme song overriding. Note that the music only overrides the 'default' music (it varies based on the situation) when a player is within proximity of either, and of course that this only applies when they're opposing NPCs.
In Samurai Warriors 2 Empires, the default theme for the stage is changed to Tadakatsu's theme while you play as him. You can still change it to something else if you wish.
Boss battles in Skies Of Arcadia are accompanied by music that changes according to how well the player is doing. If the player's party has taken a lot of damage, the music is ominous and fractured; if the player is only a few turns from victory, it's upbeat and triumphant.
The final boss battle in Persona 3 is accompanied by a remix of Burn My Dread, the game's theme tune. It's appropriate for this trope because as the battle progresses, the Main Character powers up his final ability.
Pretty much all the music in Persona 3 was awesome, but every version of Burn My Dread has the ability to either rock you in the face or punch you in the soul. The version in the final battle is incredibly tense, but also uplifting, with the slow rise of the chorus in the background and the solid, rhythmic hip-hop lead vocals creating this eternal escalator of pumped-upness. And once you've played that scene, you'll never be able to hear it without hearing Shinji helping you out.
Alternatively, when you're visiting P3's town on the sequel, the ambient music is from the third game. Crowning Moment of Heartwarming for those who loved the last edition, and a brutal change from the original pace of the game, which is heavily pop influenced.
In Phantasy Star III, the world map theme adds instruments and background to the main melody as more characters join your party. However, if the main character of the generation falls in combat, a much more tense and negative tune plays until said character is resurrected.
This occurs at least once in each chapter of Live A Live, usually using that particular chapter's battle music. A notable example is during the Mecha chapter's giant robot Buriki Daioh (whose theme music is acknowledged by an NPC saying "Start the music!" whenever the player tries to activate it). Also notable is that the game's main theme is used as the battle music for the final chapter, making nearly every battle a Theme Music Power Up.
Sa Ga Frontier had Alkaiser's theme, which plays Once Red receives his upgrade to superhero status, when you fight Shuzer the 2nd time and when you fight Arachne (Cindy Campbell)
Musical motifs from Exdeath's already evil and imposing theme in Final Fantasy V are used in his even more awesome personal battle theme.
During an optional boss fight near the end of the game, a certain song starts playing when it becomes apparent that the party can't win. The song is Gilgamesh's theme song, "Battle at the Big Bridge", and sure enough he shows up to save the day.
In Age of Mythology, when the player's units attack an opponent's major buildings (Town Center, Palace, etc.) the music switches to a more stirring track.
Played for laughs in Monkey Island 2, when Guybrush swinging heroically to grab a chest prompts the Indiana Jones theme tune. Then it's quickly subverted as Guybrush is left hanging from the rope and the music meekly fades out.
In the arcade game Fate/unlimited codes, when Archer gets to the "Yet, these hands will never hold anything" part of his chant, the regular background music cuts off and "Emiya" kicks in. Unlimited Blade Works ownage follows.
This happens in the original Visual Novel as well. As soon as Emiya starts playing, ass will be thoroughly kicked. By Shirou, a good 90% of the time. If Asskicking was a country, "Emiya" would be the national anthem, and Shirou would be the Grand Emperor.
Fate/Extra does this for all three playable servants, whenever a character uses their Noble Phantasm the scenery changes and their personal leitmotif plays for the duration.
The final boss battle of La-Mulana begins with normal-sounding boss music...which gets replaced by a remix of the Surface music, "Good Night Mom," in the boss's subsequent forms.
It was an interesting touch on the developers' part that all of the boss themes in the game open with the same chord sequence, with some remixing between each theme... except for the theme for the final boss's true form, which instead shares it's first few notes with an alternate version of the main ruins theme that only plays the first time you enter the ruins.
In Cave Story the battle with Ballos has three different songs. His first form is accompanied by "Gravity," the normal boss music. Then when you reach his second form, the music switches over to "Eyes of Flame," which is usually reserved for more dangerous bosses. Finally, his third and fourth forms come with a side of "Last Battle," the background music to the battle with the Undead Core.
The Final Battle of Ōkami. The protagonist: Amaterasu, Sun Goddess. The enemy: Yami, Lord of Eternal Darkness. The name of the song: "The Sun Rises." Yeah, the Final Boss doesn't stand a chance.
In the game God Hand, the song that plays in the first level, the western-style one is an awesome surf song called "Gene's Rock-A-Bye". Whenever Gene unleashes his God Hand, a much faster version of "Gene's Rock-A-Bye", called "Broncobuster" plays, even drowning out the themes of bosses he's fighting. Even Azel, who has the Devil Hand and his own Theme Music Power Up (from "Devil May Sly" to "Duel Storm") can't win against "Broncobuster".
Grand Papillon (AKA Joachim Valentine) from Shadow Hearts: Covenant plays this semi-straight several times throughout the game, and parodies it in one scene. During his first fight with Veronica, though not actually the first time you meet her in the game, Joachim is beaten around rather badly until Yuma throws his trademark mask to him. he crawls toward the mask and puts it on. Cue dramatic theme music and a lensflare, after which he proceeds to win the battle without breaking a sweat. The parody comes from the fact that the mask in no way helps him — it's all in his head.
The Space Channel 5 games also feature this trope. In the first one at the end, when Ulala is fighting Blank, the music starts with a small, acapella version of the game's theme song "Mexican Flyer". The better Ulala does in the battle, the more voices join in with the singing. As she gets closer to winning, even real instruments start to play, finally culminating in a thick and triumphant rendition of "Mexican Flyer" as Ulala defeats the Big Bad.
Similarly, the final battle of the second game, Space Channel 5, Part 2 features Ulala fighting against the new Big Bad named Purge. The song that plays there is called "Connected Hearts" and is also a triumphant rendition of "Mexican Flyer", complete with the characters singing lyrics to it!
Play with the Spartans in Sid Meier's Alpha Centauri, and every time your troops are fighting you'll hear an absolutely badass heavy metal theme.
Rise of Nations replaces the usual ethnic rhythms with military fanfares every time your troops are kicking some enemy ass.
While you can choose the music playing in the earlier Command & Conquer, in Tiberian Sun: Firestorm, when Cabal activated his last line of defense, a huge and powerful Humongous Mecha, the song "Slave To The System" immediately plays unless you switch off the music. This applies for both GDI and NOD versions of the mission.
Also in Command & Conquer: Red Alert 3, the background music immediately changes when the player's unit is engaging the enemy in battle (and likewise changed again when the battle ends, to different songs depending on whether you won or lost).
Def Jam: Icon is the literal embodiment of this trope. When two players fight, they each choose a song. Whomever is winning the fight will have "their" background music playing (and the background shimmies and dances to its beat). Certain areas of the level explode during bass hits, and the fighters actually control the music by making DJ scratching motions in the air to wound their opponent. See how it works here, though the lyrics are NSFW.
Keeping up with the Final Fantasy references, the last true boss of Final Fantasy X is heralded by a massively muscled arm clawing up to a platform — and much more importantly, metal guitar.
The "Challenge" soundtrack really comes into its own as a TMPU in the way it builds up in the cutscene in The Beyond and its peak when the fight against Yunalesca finally begins.
In Shadow of the Colossus, the music is usually a mournful, slow-moving tune when you start fighting a colossus, but when you grab onto the thing and prepare to stab, the music swells into a louder, (usually) faster, and more awesome song that certainly fits the theme of you stabbing a thing well over 10 times your size to death. And when you realize you're pulling a Nice Job Breaking It, Hero, the music turns bitterly ironic.
In Elite Beat Agents, the agents fight off against music-hating aliens by getting everybody in the world to dance to an absolutely epic cover of The Rolling Stones' Jumping Jack Flash. In fact, the entire game (as well as the Ouendan series it's based on) revolves around this.
In Ace Combat Zero, whenever something particularly awesome happens the latin guitar from the final boss fight kicks in for a short duration. And of course there is that final boss music.
Ace Combat 5 has "The Unsung War", which combines your theme song with Ominous Latin Chanting for 7 minutes of awesome. Did I mention the fact that you're shooting down a SATELLITE while being attacked by the best aces of the last war?
The entire series has a tradition of playing the game's main theme during the climactic battle.
In the original Persona, during battles where a new party member is introduced, the game uses a special battle theme called "Awakening". In these battles, the character(s) in question go from being regular high school students to full blown Magic Knights.
The original Star SoldierShoot 'em Up for the NES changes the music when you power up...and in a later remake for the PS2, GCN, and PSP a rock remix of the power up theme plays. AWESOME.
In the console version of BlazBlue, if a player performs Bang Shishigami's Furinkazan super move, the music suddenly changes to a brand-new song by Hironobu Kageyama called "Omae no Tetsui ni Kugi wo Ute". It's an over-the-top song about how much of a Hot BloodedBadass Bang is. And it is awesome.
And in the console version of the sequel, Continuum Shift, when you perform an Astral Heat), the chorus of the opening song plays in the background.
Disgaea is fond of this. An interesting point is Kurtis' awesome return, which makes the music his theme by default.
Also, the anime switches to an instrumental version of Lord Laharl's Hymn whenever the Prince gets angry. But that's nothing next to what The earth SDF does when their theme music is first played.
Tales Of The Abyss has this used against the party in the optional Arena battle with four previous Tales characters; at first, the game is playing "Everlasting Fight," which is a medley of previous Tales battle themes. If you don't defeat them fast enough, Reid will activate Aurora Wall...
Reid:We will notLOSE!!
...revive any of his fallen party members, deal tons of damage to you, and a remix of "Eternal Mind" suddenly starts up. This is about when any average player goes "Oh Crap."
Earlier than that, the songs 'The Power of a Pure Heart and the Path to the Distant Future' and 'Bitter Enemies in the Same Boat' are both used at powering-up points (namely, the end of the Heart-to-Heart and when Sagi first gets the power to destroy machina arma, respectively).
The final boss of Devil Summoner 2: Raidou Kuzunoha vs. King Abaddon, comes in three stages. The first stage has a unique battle theme, the second is recycled from earlier, but the third plays Raidou's theme, as a nice reminder of just how epic he is.
The themes of the final boss isn't about how grand he is as much as it is about Raidou kicking his ass.
Tales Of Symphonia: One of the playable characters, Kratos, has his own theme tune that plays slowly. However, during a certain event in the game, a faster, more upbeat and more complex version is played.
The Double Dragon title theme is played during the final battle in the first game instead of the usual boss theme. Return of Double Dragon (the Japanese version of Super Double Dragon) is the only other game in the series to do this as well.
Oddly, in the NES version, the music switches to the City Slum theme when you fight Jimmy.
One of the best things about Half-Life 2 is that music is only played in certain situations, the rest of the game is devoid of BGM. This usually translates into intense battles cranking things up to 11 by adding music. The mad dash through the canals in the Water Hazard chapter or the showdown with the strider in Episode 1 comes to mind.
You can gauge whether or not it's safe to let your guard down by whether or not the music's still playing.
Episode 2, when every alarm goes off in the underground.
Whenever a character enters Border of Death mode in Touhou Soccer 2, the character's accompanying theme takes over as the BGM briefly (assuming that a theme exists).
Gengetsu, the Bonus Boss of Touhou: Lotus Land Story gets a remix of the game's title theme. Needless to say, this is your signal that the fight will be a little intense.
An Easter Egg in Touhou Hisoutensoku includes this. If Reimu is able to successfully pull off the Fantasy Heaven spell card in Round 3 of a fight, a remix of her theme (only accessible through that spell card) plays in addition to a 330-hit instant KO.
And from the "mainstream" Windows Touhou games, Yuyuko, the final boss of Perfect Cherry Blossom, gets one of these when she activates her final spell.
Used as a game mechanic in Beat Hazard, the more intense the music you plug into it, the more powerful and more spread your shots are. You can also grab volume up powerups to make it that much better. On the other hand, intense music makes explosions larger and makes enemies and their shots that much harder to see.
In Pitfall II: The Lost Caverns every time you grab a treasure or rescue someone a galvanizing, heroic, upbeat theme vaguely reminiscent of the Indiana Jones anthem plays. One of the oldest ones in the book, as it was the first console game to feature PSG music, in fact the only 2600 game to have a custom sound chip.
Also whenever you hear Reunion in Threads Of Fate. Expect something awesome will happen
In Bomberman Generation, the boss battles start off with a slower, more foreboding version of the game's Theme Song. However, when the titular hero brings a boss's health down to critical levels, the music changes to the main theme.
The final boss of Ikaruga cuts the music for its final form and starts up "Stone Like", a remix of the first level's theme. As an added bonus, if you play your tennis right, the boss explodes right at the end of the musical phrase.
Meridian Dance plays when the Sword is finally revived in Secret of Mana.
The theme song to the show-within-a-gameSplit/Second. Plays during the Elite races, which will most likely be the point of highest tension. Dynamically changes as you pull ahead or fall behind. Only serves to make whatever victories you can pull off against the most springy of Rubberband AI sweeter.
Saints Row The Third has -three- Theme Music Power-Up moments. "Power" by Kanye West plays when you parachute onto a rooftop party held by the Syndicate and take the building over for the Saints. Later, in a wrestling match with the head of the Luchadors, Killbane, and you have to fend off a ton of his lackeys with a chainsaw, you get You're The Best Around. Finally, The Boss is forced to choose between killing Killbane before he skips town or rescuing Shaundi and Viola from a STAG plot to blow up the Statue of Liberty expy and frame the Saints. If you choose the latter, this plays. There are no words.
In Sengoku Basara when either Ieyasu or Mitsunari face off against each other in the end of their story paths, "Naked Arms" will play in the background. Also, characters will have their Leitmotif play whenever they're fought.
Inverted in the final boss fight of Nie R, where the Shadowlord's very powerful theme gets weaker and weaker as the fight progresses until all that's left is a music box rendition of his theme for his final sliver of health.
In The Elder Scrolls V Skyrim, "One They Fear," a triumphant version of the main theme that occasionally plays during boss fights, certainly feels like one if you can beat the boss before the song ends.
The last stage of PN 03 uses the full version of the attract/intro music.
In Win Back, the final boss battle with Cecile reuses the opening theme.
In Bleach: The 3rd Phantom, whenever a character activates their Bankai or Release, in Grimmjow's case, an instrumental version of the game's theme song plays. Same with the cutscene where you acquire (depending on Free Time choices) either Rengoku, Rasen, Shunko, or Bankai.
The climax of the Galaxy Angelgames always follows the Theme Song variant, playing that year's version of Eternal Love (or, in Galaxy Angel II games, Wing of Destiny).
During the boss battle against Vic Viper in Zone Of The Enders: The 2nd Runner, a remix of the Gradius boss theme, Aircraft Carrier, will be heard playing during the fight, complete with the crowd in the song chanting "Leo, Leo, Leo, let's go!" since the Vic Viper is piloted by the first game's protagonist Leo Stenbuck.
Men are about courage, bgm that was played each time Yamato or any other male character get their Moment of Awesome .
Sword Dance, bgm that was played each time Mayucchi get serious in her battle.
Bushi, song that was played during the battle between Momoyo against three deva of the martial art which is played when the Otome the last of four devas appears to help Mayucchi and Ageha to defeat Momoyo.
Phoenix Wright: Ace Attorney uses this trope to extremes unplumbed by man, playing it straight and subverting it at will as the case swings back and forth in and out of Phoenix's favor. A Double Subversion occurs in the first game's third case: Phoenix is out of ammo, the witness/killer is about to get off the stand... and then "Investigation ~ Cornered (Variation)" (very dramatic and heroic music) starts up as Edgeworth objects to keep the witness on the stand. The music dies as Edgeworth realizes he doesn't have a question, the judge is about to let the witness go... and then the music starts up again as Edgeworth has a burst of inspiration.
Note that in the second trial, when Phoenix first has White about to confess the music starts up for Edgeworth as he proceeds to help weave a false testimony, triggering part two of the confrontation. The music starts up again when Wright has White cornered for the second time, and Edgeworth attempts to obscure the truth once again by extending the trial.
The second game uses this in an interesting way: Edgeworth returns from a Journey to Find Oneself. Part of the sign he found what he was looking for is that he has gained his own theme music.
This happens again in Trials and Tribulations when Phoenix finally backs Godot into a corner, exposing as the true "murderer" of Misty Fey. As he does, the "Cornered" song from the first game reappears. Mia Fey's spirit even shows up to cheer Phoenix on.
In fact, the use of this trope verges on being a gameplay element — whenever you present the correct evidence at a contradiction, the cross-examination theme willalwaysstop as Phoenix objects, in preparation for the heroic music to start up once he points out the contradiction. If you're wrong, the music will just keep going as he takes a penalty. Save right before every objection you're not sure of, and wait for the music cue with your finger on the power switch in case you were wrong...
And in the second to last piece of evidence of the third game (the one with the first game's "Cornered" theme) the music always stops and Godot's next line is the same if you present the right piece of evidence or not.
In the fourth game, the prosecutor was a guitarist for a band and his theme music turned out to be one of his actual songs. Further, he will perform awesome air guitar in court, which does everything from double your penalty bar to break down a witness.
Don't forget Godot. He has his own smooth jazz Leitmotif as his CELL PHONE RINGTONE.
Appropriately, this carries over to Phoenix Wright's appearance in Ultimate Marvel vs. Capcom 3. While his normal theme song is the first game's "Objection!", whenever he gathers enough evidence to go into Turnabout Mode, this (as well as any other theme that is playing) will be replaced by the iconic "Cornered" theme.
Remember Edgeworth's awesome theme song from the second game? The one that became the Big Damn Heroes theme song for the next two games? It's received a remix on his own game, Ace Attorney Investigations, to be his Objection! theme. And on the second one, it's basically the ground stone for every theme involving him.
The Adventures of Dr. McNinja has to sing along to the Ghostbusters theme in order to empower himself to do battle with ethereal beings. Not the lyrics though, just the tune: "Dada, Dadadada!" The technique is common to all ninjas, although methods vary; only the Doctor actually requires the Ghostbusters theme specifically.
Namine: Okay, we stopped Cloud, but do you think there might be a reason that this song was on Axel's murder mix CD?
Zexion: Oh shit...
[cut to Axel setting everything on fire]
For a webcomic, Homestuck has a lot of songs used in this fashion for flash updates, but the best example is probably "Sburban Jungle", which was first used for the Loading Screen when John installed Sburb. However, it gets remixed for both the End of Act 3 and Act 4 animations to signify that some seriously awesome shit is going down.
John's theme, Doctor, gets the same treatment, eventually being hijacked by Jade in Cascade.
Atop The Fourth Wall: Although not his own theme song, [[Linkara]] makes use of the Power Rangers theme song when, after being beaten to a pulp by his cyborg counterpart Mechakara, he gets an Heroic Second Wind and morphs into "Internet Reviewer," after which he proceeds to kick Mechakara's ass.
Red vs. Blue: After the animation got kicked up the series started denoting the shift into the epic CGI action phases with this trope.
Averted in "Leapfrogs: Numbers Ahoy!" When the young male protagonist mispronounces the villain's name, the dread!Theme actually pulls itself off the record.
The Real Ghostbusters. The chorus and some of the instrumentals from the Ghostbusters theme song would sometimes play, typically starting during formulation of the plan (which is usually Crazy Enough to Work) to defeat the episode's Big Bad, and then afterwards during the Final Battle with the Big Bad itself; which often also involved Egon coming up with a brilliant Indy Ploy during combat.
The Popeye cartoons, with Popeye's spinach-induced theme music.
Some could say the original shorts were among the earliest innovators of this trope.
A particularly awesome example comes from the episode "Disappearing Inque". Terry gets kidnapped by the villainess Inque, and she threatens to kill kim unless Bruce shows up. Later on, we see a large figure in a trench coat walking towards Inque... which turns out to be Bruce, in a massive Batman mech suit. The moment he starts whaling on her, an orchestrated version of the Batman theme from Batman the Animated Series starts playing.
Something similar happens in another episode where Bruce, rejuvenated by a couple dips into a Lazarus Pit, fights side-by-side with Terry, with the BTAS theme going, except it's electric guitars instead of trumpets soaring.
Parodied in the South Park episode "Towelie", as whenever the titular Towelie got high, Popeye's theme music played and Towelie became dumber than he already was.
Most of Kim Possible's flipping, fighting, and swinging is accompanied by a guitar-and-strings action leitmotif that's re-used in every episode. A few of the recurring villains also get their own theme music; the mini-episode "Adventures in Rufus-Sitting" features a four-way fight in which the soundtrack changes several times in the space of a few minutes to reflect whichever combatant currently has the upper hand. Check out this clip.
The FuturamaOVA "Bender's Big Score" has the climactic battle with the theme playing the background.
The fifth season finale of Teen Titans (not counting the last-last episode) has a particularly stirring version of the show's theme playing during the final battle with the Brotherhood of Evil.
Played at the climax of "The Drill" in Avatar The Last Airbender, as Aang hands Azula one of her few outright defeats in the series.
Not to mention during the Season 2 Finale, any time Aang enters the Avatar State, and most especially during the climactic fight with Fire Lord Ozai. One of the coolest versions ever actually plays during the end credits after the series wraps up.
Side note: Aang's theme song is actually a remix of the main theme.
Same motif is played during a flashback episode featuring Aang's predecessor, Avatar Roku, describing the amazing power he became master over when he learned all the bending arts.
Optimus Prime of Transformers Generation 1 still has "The Touch" in "The Return Of Optimus Prime" when he opens up the Matrix of Leadership to wipe out the Hate Plague. His eventual successor, Ginrai, gets the rather cool "Don't Cry".
In ThunderCats, Lion-O got to trigger his own theme music when he powered up the Sword of Omens. Ta-ta-TAA! And not only did he get to start kicking ass, but all the other Thundercats, no matter where or how captured/restrained they were, could see the Lion-signal, hear the roar, and naturally break free.
This also applies to the other Thundercats with their own Leitmotifs any time they're kicking ass individually. Panthro's can be especially epic, as the Leitmotif itself gets powered up if he's doing his ass-kicking in the Thundertank.
In the first two season finales of X-Men, a particularly rousing take on the show's theme backs up the heroes in the final battle. Then the third season started applying it to roughly every other fight they got into, and it kind of lost its potency.
Even in the Live Action movie, where He-Man has no alternate persona and therefore doesn't have a transformation sequence, gets a musically enhanced Power Up when necessary. He Has The Power!
In Code Lyoko, William gains a personal music theme in Season 4 after he turns evil. It follows him in each of his subsequent appearances, which are generally the most intense fights in the show. (He isn't always victorious, though.)
On Lyoko, the sound effects seem to be having fun whenever the gang's about to win or lose.
Inspector Gadget used this all the time: a version of Penny's theme would often play just as she's about to turn Dr. Claw's newest scheme upside down. Brain would occasionally get these as well, but less often (more often his theme would be played during particularly funny scenes).
Any time that Captain Planet is summoned. Most of the time it's the title theme, but there are a couple of other music cues that are equally awesome.
In the first episode of the '80s Ninja Turtles toon, the turtles discover that the Foot Ninja they're fighting are actuallyrobots, and the theme music starts up as they proceed to go to town on them.
The Eighties loved this one. On Galaxy Rangers, once you heard the electric guitar music, you knew something awesome was coming in.
On Lilo & Stitch: The Series, the show's theme song "Aloha E Komo Mai" would usually play in an upbeat rock format whenever Stitch or someone else was kicking major butt.
In The Big Knights, whenever Sir Morris and Sir Boris are about to perform their idea of heroics (which usually means smashing everything), the show's thunderous orchestral theme music kicks in.
The season one finale of Generator Rex uses the theme tune when the heroes take back their headquarters from Van Kleiss' forces.
In the first Shrek film, the familiar strings of Joan Jett's "Bad Reputation" start to play when things start to turn in the titular ogre's favor during the wrestling match in Duloc.
Probably an odd case combined with He's Back in Shrek2, when Shrek, Donkey and some of the others race to rescue Princess Fiona while the Fairy Godmother's singing "Holding Out For A Hero".
Thomas And Friends sometimes does this whenever one of the engines does something particularly competent. Perhaps most notable for James, who actually had a slow dramatic version of his theme to play when he was triumphant (eg. taming an exceptionally unruly bunch of trucks).