[[quoteright:505:[[WesternAnimation/{{Bluey}} https://static.tvtropes.org/pmwiki/pub/images/blueybingo.png]]]]
[[caption-width-right:505:Well, this look peculiar...[[note]]'''Top''': Every episode. '''Bottom''': [[Recap/BlueyBingo Bingo]][[/note]]]]

A show's [[ThemeTune theme song]] is an important way that a show distinguishes itself and sets the tone for the series. It also gives a chance to feed the ego of the stars. But sometimes the regular theme song doesn't fit an [[UnexpectedlyDarkEpisode abnormally serious episode]], or the show is doing something special and wants to highlight it with a new arrangement.

In this case, the creators will replace the stock theme song. But the important thing that makes this different from EvolvingCredits is that they then return to the original theme song. If the theme song changes for nearly every episode, then it's a CouchGag. If the theme song is different from one season to the next, but is consistent within each season, it will fall under AnimeThemeSong, EvolvingCredits, or RearrangeTheSong.

Compare to CreditsGag, DiegeticSoundtrackUsage, CouchGag, and (not to be confused with) ThemeAndVariations.

May overlap with VariableMix if the song changes mid-tune.

May also overlap with {{Leitmotif}} if the modification to the theme song has to do with the introduction, feature, or progression of a unique character associated with style of music used in the modification.

May overlap with SpecialEditionTitle, which includes all modifications to normally consistent opening audio/visuals (including studio logos, theme songs, etc.).

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!!Examples:

[[foldercontrol]]

[[folder:Anime & Manga]]
* ''Anime/AngelBeats'': During [[TheCutie Yui]]'s introductory episode, fitting to her personality, she sings a rock version the opening ''My Soul, Your Beats!'' (originally an upbeat pop song) at the end of the ColdOpen.
* Some episodes of ''[[VideoGame/PriPara [=PriPara=]]]'' end with a different song than the current one for that cour that were only used once:
** Episode 71 ends with "Thank You Birthday".
** Episode 73 ends with "Pure Amore Ai"
** Episode 122 ends with "Brand New Dreamer!"
** The second-to-last episode of ''Idol Time [=PriPara=]'' ends with "Rainbow Melody", while the final episode ends with "Believe My Dream!".
[[/folder]]

[[folder:Asian Animation]]
* ''Animation/PleasantGoatAndBigBigWolf'': The original theme song was first done by by Ivy Koo, but ''Joys of Seasons'' uses a version by Yang Peiyi.
[[/folder]]

[[folder:Film Studios]]
In general, most film studios that employ a specific theme track have employed different variations of that track depending on the specific film/TV it produces. This includes 20th Century Studios, Warner Brothers and Walt Disney Studios.
[[/folder]]


[[folder:Live-Action TV]]
* A 1988 Creator/{{CBS}} edition of ''48 Hours'' (now ''48 Hours Mystery'') focusing on the poverty-stricked Appalachian region of Kentucky had the regular theme at that time remade to [[https://www.youtube.com/watch?v=vLK33215T84 include a banjo]].
* Most episodes of Creator/KenBurns' 1994 documentary ''Baseball'' begin with a standard concert-band rendition of "The Star-Spangled Banner," emulating what happens at a real baseball game. But episode 8 begins with the version Music/JimiHendrix played at Film/{{Woodstock}}, to reflect changes in the sport and turmoil in the country during the 1960s.
* ''Series/MrBean'' did this on a few occasions: a Christmas episode has a jolly version of the theme track, and one episode that had Bean on a trip to Russia featured a Russian-styled version.
* ''{{Series/Blackadder}}'' had a [[RearrangeTheSong different theme for each season]]. However, there were also a few single-episode variations.
** The final episode of the first season had a rearranged, sadder version of the theme with different lyrics.
** In the second season, the lyrics to the closing theme were different in each episode, recapping the plot.
** After the DownerEnding of the final episode of the fourth season, the closing theme is played very slowly on piano.
* ''Series/BuffyTheVampireSlayer'': in the musical episode, "Once More With Feeling" (S6-E7), the usual theme song by Music/NerfHerder is changed to an classical styled orchestral version.
* ''Series/{{Community}}'':
** "Abed's Uncontrollable Christmas" had Abed singing a Christmas-themed version of the theme song.
** "Advanced Dungeons and Dragons" has the theme song performed by an orchestra.
** "Basic Lupine Urology", an episode spoofing ''Series/LawAndOrder'', had the theme song performed with ''Law And Order's'' instrumentation.
** "Digital Estate Planning" had the theme song performed in the style of an 8-bit video game's BGM.
** "Grifting 101" had the theme song performed on a piano similar in style to the theme song from ''Film/TheSting''.
** "Emotional Consequences of Network Programming" has the study group members imagining what the show would be like if they had gotten a seventh season. Britta imagines a nihilistic version of the show with a DarkerAndEdgier version of the theme song.
* ''Series/{{Crossroads}}'': Particularly dramatic episodes sometimes used the cover version of the theme tune done by Music/{{Wings}} on their ''Venus and Mars'' album.
** At least, that's how it was ''supposed'' to work. In fact there seems to have been some confusion amongst the production staff, which resulted in the two versions being switched more or less at random.
* Soap Opera ''Series/DaysOfOurLives'' featured a grander fully orchestrated during the ''Salem Stalker'' storyline in 2004 before going back to the original composition.
* ''Series/{{Dexter}}'': in the Season 4 opener, the normal sequence of Dexter preparing his day along to the theme song is replaced with a much more drowsy and disjointed sequence to represent his exhaustion at this point in the story.
* ''Series/DoctorWho'':
** "[[Recap/DoctorWho20thASTheFiveDoctors The Five Doctors]]", the show's [[MilestoneCelebration 20th anniversary special]], starts its end credits with the original 1963 theme pitch shifted to match the then-current variation, before transitioning into the current theme just before the middle eight.
** "[[Recap/DoctorWhoS35E4BeforeTheFlood Before the Flood]]" ends its BreakingTheFourthWall ColdOpen with the Doctor rocking out on electric guitar, [[CastingGag just like the band he was in]], which continues over the opening credits.
** "[[Recap/DoctorWhoS37E6DemonsOfThePunjab Demons of the Punjab]]", which is set on the borders of India and Pakistan in 1948, has an Indian-styled rearrangement of the theme for the end credits.
* ''Series/TheDrewCareyShow''
** In one episode the RealSongThemeTune "Cleveland Rocks!", normally sung by Music/ThePresidentsOfTheUnitedStatesOfAmerica, is sung by Music/TheGoGos.
** The final season has the theme performed differently every episode.
* The ''Series/{{Farscape}}'' episode "Scratch 'N' Sniff" replaced the usual closing music with the lounge-jazz soundtrack from a nightclub scene in the episode.
* ''Series/GoodOmens'':
** The penultimate episode end credits, with the Apocalypse in full swing, have a doom-laden organ rearrangement of the theme.
** The final episode replaces the closing theme with Music/ToriAmos performing "A Nightingale Sang in Berkeley Square".
* ''Series/HowIMetYourMother''
** S9-E11 - The theme song is modified to sound like a children's music box.
** S7-E14 - Barney claims to be the leader of the gang, and the song's words are changed, as well as the photos in the opening credits. Then later in the episode, the them song is sung again in Russian when Stripper Lily joins the group.
** S6-E21 - After Barney claims the group is in a band, the theme song is sung by the main cast.
* For the ''Series/{{Monk}}'' episode "Mr. Monk and the Rapper," guest-starring Music/SnoopDogg, he did a rap cover of the show theme song "It's a Jungle Out There", although the original variant by Randy Newman plays in the closing credits.
* ''Monster House'' (the makeover show, not [[Film/MonsterHouse the movie]]) did a special arrangement of its theme song for their HalloweenEpisode. The normally peppy, upbeat song is played gloomy and dark with a deep voice singing instead of the normal calm voice. Also, the next to last line is changed from "And we all just love it" to "And we've all gone missing."
* ''Series/{{Neighbours}}'': Has two versions of its theme song - the usual, upbeat version and the stripped-down piano version reserved for when someone dies.
* While the opening version of the ''Series/NightAndDay'' theme tune (Kylie Minogue's ''Always and Forever'') was always the same, unusually there were four alternate versions of the closing, which were used on rotation: an extract from the chorus, two extracts from verses, and an instrumental version of the chorus which was increasingly used towards the end of the run.
* ''Series/OneTreeHill'' originally used Gavin [=DeGraw=]’s “I Don’t Want To Be” as the opening theme song for the first four seasons before abandoning the tile sequence at the start of the fifth season as the show jumped ahead four years after high school graduation. Going into the eighth season, everyone involved in the show was expecting that to be the final season and so the “I Don’t Want To Be” opening was brought back, with the show using a variety of cover versions throughout the season and [=DeGraw=]’s original being used at certain specific points to indicate a significant episode.
* The quiz show ''Series/OnlyConnect'' sometimes does this. After the S13 final pulled a DiegeticSwitch by using the regular arrangement but played live by a string quartet, subsequent finals have featured the tune being played on a barrel organ, and sung by an a capella group, in both cases actually present in the studio.
* ''Series/{{Outlander}}'' has subtly changed its theme music (an arrangement of a modern Scottish folk song, "The Skye Boat Song") several times to reflect the varying locales of the storyline:
** When the setting moves to France in season 2, parts of the lyrics were rewritten in French, and the music was given a more baroque feel.
** In season 3, as the main characters planned to leave Scotland, the Celtic instruments were removed entirely. When Claire and Jamie travel to Jamaica, the theme now has an "island" beat with drums.
** In season 4, the duo travel to America and the theme now has banjos for a "folk" feel.
** For season 5, the theme switched to a gospel choir rendition, reminiscent of the American south.
** Season 6 switches to a duet with both a male and female vocalist.
* ''Series/{{Poirot}}'' episodes set in foreign countries sometimes rearranged the title theme in appropriate style for AdBumpers and closing credits.
* ''Series/{{Psych}} ''
** S2-E10, S3-E9, S5-E14 - A Christmas variation on the theme song.
** S2-E13, S7-E4 - The theme song is sung in Spanish.
** S4-E6, a Bollywood variation on the Theme Song.
** S4-E7, S6-E13 - The Boys2Men a capella version
** S5-E8 - Curt Smith recorded a version of the song.
** S5-E12 - The Julee Cruise version of the song
** S6-E4 - A superhero-themed version
** S6-E11 - A theme song tribute to ''Film/TheShining''
* ''Series/{{Qi}}'':
** In the annual Christmas episodes, the theme is combined with "Jingle Bells".
** The series F episode "France" has the theme played on concertina.
** The series G episode "Gothic" has funeral bells and a baying wolf in the background of the opening theme.
* ''Series/RedDwarf'':
** In one episode, there was a throwaway gag about Rimmer teaching the service robots to play Hammond organ. The closing theme for the episode is rendered on the Hammond organ, with Rimmer giving instructions in voiceover.
** For the "cowboys" episode "Gunmen of the Apocalypse", the theme is given a {{Western}} makeover on honky-tonk pianny and ''Film/TheGoodTheBadAndTheUgly''-esque ocarina.
** The episode where the Dwarf visits a planet with sentient celebrity wax figures has the ending theme performed by the wax Music/ElvisPresley.
* For a season 3 arc of ''Series/SonsOfAnarchy'' that took the crew to Ireland, the theme tune was given an Irish strings-and-flutes rearrangement.
* The ''Series/StarTrekEnterprise'' episode "In a Mirror, Darkly" is set entirely in an alternate universe, which extends to the intro. So instead of showing pictures of early Starfleet history as we know it, it shows pictures of the ''alternate'' history. Also, the theme song "Faith of the Heart" is not playing; instead, a different, instrumental tune is.
* ''Series/StarTrekStrangeNewWorlds'' does this twice in a span of three episodes, both times for comic effect. First, "Those Old Scientists," the CrossoverEpisode with ''Series/StarTrekLowerDecks'', has animated credits in the style of that series (complete with comical monsters). Then, in the MusicalEpisode "Subspace Rhapsody," the theme music is replaced with a cappella vocalizing.
* ''Series/TalesOfTheUnexpected'': The series 4 episode "The Boy Who Talked With Animals" has the ending credits theme replaced with a variant played on steel instruments, reflecting the Caribbean setting of the story.
* ''Series/ThirdRockFromTheSun''
** Alternate versions were used during Christmas episodes
** In Season 6, a alternate jazz version of the song was used for the two-part episode
* ''Series/{{Warehouse 13}}'': The theme is changed for Christmas specials.
* ''Series/WheelOfFortune'' occasionally uses a different opening theme for episodes taped on location.
* In November 2018, ITV randomly changed the theme songs on several of its programs (including ''Series/CoronationStreet'', ''Series/{{Emmerdale}}'', and more ridiculously, ''Series/{{The Chase|GameShow}}'') to piano versions. It was eventually revealed to be a tease for the Advertising/JohnLewis Christmas ad, starring Music/EltonJohn.
[[/folder]]

[[folder:Podcasts]]
* ''Podcast/TheAmeliaProject'' often uses remixes or covers of its own theme song fitting the episode's story or setting. The Christmas episode "Mr. Love, Actuary", for example, adds jingle bells to it in the opening and a cover using the instruments of the ''Film/LoveActually'' main theme before the epilogue.
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[[folder:Radio]]
* Although long-running BBC radio soap ''Radio/TheArchers'' always uses the same piece of music as its theme tune, which passage is used depends on whether the episode is ordinary or dramatic.
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[[folder:Video Games]]
* The ''Meet the Team'' videos in ''Videogame/TeamFortress2'' had a few variations on the end title.
** ''Meet the Demoman'' had bagpipes.
** ''Meet the Spy'' had stabbing noises in beat with the tune.
[[/folder]]

[[folder:Web Animation]]
* ''WebAnimation/{{TOME}}'': There's quite a few variations for TOME's theme song [[http://tomeseries.bandcamp.com/track/battle-on "Battle On"]] starting with the [[http://tomeseries.bandcamp.com/track/battle-on-orchestral-version Orchestral arrangement]] in episode 06. There's also a chiptune arrangement in the 4th short, a [[http://tomeseries.bandcamp.com/track/battle-on-rock-and-roll rock and roll]] version in episode 08, and a [[http://tomeseries.bandcamp.com/track/battle-on-smooth-jazz Smooth Jazz]] version in episode 09.
[[/folder]]

[[folder:Western Animation]]
* The end credits of the ''WesternAnimation/AdventureTime'' episode "The Suitor" replace the usual "Island Song" end theme with "Braco Don't Go", a song that was written to be used within the episode but eventually decided not to work with the sequence it was intended for.
* ''WesternAnimation/{{Animaniacs}}'':
** The Christmas-themed episodes have an alternate intro with a snow falling effect and jingle bells chiming in the background.
** Episode 56 has the theme sung in French.
* ''WesternAnimation/BigCityGreens'':
** "Blood Moon": The theme becomes a spooky minor [[{{Tonality}} key]] complete with a theremin, and has scary images and a RedFilterOfDoom.
** "Chipocalypse Now": The theme is done in a [[DarkReprise minor key]], complete with [[HostileShowTakeover Chip hogging some of the shots]], depressing scenes such as the Greens' neighbors leaving Big City and the demolished Big Coffee and apartment complex, and the partially finished Wholesome Foods Megastore surrounding the Greens' house.
* ''WesternAnimation/BoJackHorseman'''s normal theme tune is a peppy song by Music/{{Grouplove}}.
** "See Mr. Peanutbutter Run", an episode without [=BoJack=] and about Mr. Peanutbutter, has the lyrics changed to fit Mr. PB.
** "The Dog Days are Over", about Diane's spontaneous trip to Vietnam, has a Vietnamese cover of the song.
** "The Amelia Earheart Story" has a mandolin cover play instead, as the episode is set in North Carolina.
* When WesternAnimation/BugsBunny makes a cameo appearance in the George Pal Puppetoon "Jasper Goes Hunting," an ersatz rendition of the Merrie Melodies theme accompanies him.
* In ''WesternAnimation/TheFairlyOddParents'' [[MadeForTVMovie TV movie]] ''WesternAnimation/AbraCatastrophe'' when Bippy wished that monkeys ruled the world, we get a monkey-fied version of the theme song.
* The debut episode of ''WesternAnimation/{{Freakazoid}}'' features an alternate theme done to the theme of ''WesternAnimation/{{Animaniacs}}''.
* ''WesternAnimation/CloneHigh'': One of the very very special episodes had the song played as more of a mopey ballad.
* ''WesternAnimation/TheLoudHouse'':
** In "[[ChristmasEpisode 11 Louds a' Leapin']]", the end of the theme tune shows a winter scene instead of a black background, and baby Lily is wearing a snowsuit and snowshoes.
** In "Tricked!", Lily is shown at the end of the theme dressed as a ghost and instead of saying "Poo-poo!", she makes ghost noises.
* For the opening of the ''WesternAnimation/MyLifeAsATeenageRobot'' special "Escape From Cluster Prime", the theme starts out normally before seguing into a dramatic instrumental version with a movie like poster featuring all the characters involved.
* While ''WesternAnimation/PegPlusCat'''s theme has minor changes every episode, it's always the same characters singing the same lyrics, with these exceptions:
** In "Yet Another Tree Problem", Cat sings all the lines, with the exception of "Ten? Yeah!" which is sung by the fake audience, because Peg was stuck up a tree at the time.
** In "[[HalloweenEpisode The Halloween Problem]]", Cat once sings, "Ghost?!" instead of his name due to thinking he's seen one.
* ''WesternAnimation/TheSimpsons'':
** In the middle of an episode where they go into Witness Protection and become the Thompson family, we see a variation of the theme where the chorus goes ''"The Thompsons"'' and Homer pulls up to their new home, a houseboat.
** When a hurricane comes through town, the chorus sings ''"The Hurricane"'' and the letters on screen get blown away by the hurricane's wind.
** ''Treehouse of Horror'' episodes usually have the closing credits music replaced by an arrangement for organ and theremin. The music for the Gracie Films logo, instead of the usual piano riff with a woman going "Shhh!", is the same riff on organ with a woman screaming.
** When a rock band are the guest stars, sometimes they do the closing theme. Other episodes have arrangements related to the setting or topic of the episode, or based on the theme music of the TV show or movie being parodied. Sometimes, this also applies to the Gracie Films VanityPlate.
** Season 9 episode 1, ''The City of New York vs. Homer Simpson'', replaced the usual closing theme with "New York, New York" sung by Music/FrankSinatra.
* In the ''WesternAnimation/SouthPark'' episode "[[Recap/SouthParkS23E8TurdBurglars Turd Burglars]]", the theme song is sung by the South Park women with various clips from past episodes featuring them, proving that this episode really is "One for the Ladies".
* ''WesternAnimation/TeenTitans'' had its theme song sung in Japanese whenever the episode involved the Titans in [[BizarroEpisode extremely bizarre situations]]. There was also a one-time rendition of the song by an alternate-reality Robin (aka "Larry"), also in Japanese.
* ''WesternAnimation/TinyToonAdventures'':
** ''WesternAnimation/TinyToonAdventuresHowISpentMyVacation'' - The characters sing about how they plan to spend (and at the end, spent) their summer vacation.
** "Two Tone Town" - The Two-Tones sing about their new show and their home town.
** "It's A Wonderful Tiny Toons Christmas Special - The characters sing a Christmas-themed version of the song. Also, in the alternate timeline, Plucky is the star of Tiny Toon Adventures and sings his own lyrics describing him as the star.
** When Plucky got his own spin-off (which mostly consisted of recycled "Tiny Toons" shorts with one original episode), the lyrics described Plucky as the star in a manner similar to the example above.
** The CD "Tiny Toons Sing" has the theme song sung in different languages.
** "Spring Break Special" - The characters sing about how they plan to spend (and at the end, spent) their spring break, similar to the Summer Vacation example.
** "Night Ghoulery" - The characters sing about what they have planned (at at the end, the results) for their halloween special.
** In Tiny Toons How I Spent My Vacation Buster plays a Dueling Banjos version with a possum banjoist. Buster plays his tongue.
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