The metal cover band Ten Masked Men specialize in destroying pop classics by interpreting them all as straightforward no-frills Death Metal regardless of the origin, so this trope is to be expected from them.
Pig Destroyer's music embodies this trope. Imagine a guy screaming and wailing uncontrollably over sickening guitar tones, singing lyrics such as "She frolics through the rain whispering love insane, her kisses exit through heart-shaped exit wounds". They call themselves "pornographers of sound".
Inverted in Eluveitie's "Inis Mona". Very heavy track that sounds like it's going to be about something negative — and they're singing about a Welsh island, Anglesey! Understandable if one knows that the Welsh for Anglesey is "Ynys Mon"
Opeth has plenty of examples of mellow-sounding parts with sad lyrics (although they're often dark-sounding mellow parts). The song Deliverance, though, has a really soothing soft section with lyrics which are, fairly unambiguously, about killing someone by holding their head under water.
Intestinal Noose combines brutal death metal instrumentals with "fluffy cuddly" lyrics. The song Puppy is a prime example.
Lykathea Aflame has lyrics about spirituality and mystical energies with an Egyptian flavor - and grindcore fused with progressiveness and oriental melodies, though mostly pounding death metal/grindcore with extremely complicated drums. An example:
Tears shall bear his inner beauty and noble soul/and his body will come into flower by gorgeous aura.
This is all growled while the drummer beats the living hell out of his kit with full force and technique.
Discordance Axis's lyrics are usually very abstract and thought provoking, but their music is extremely brutal and cathartic, not to mention the lyrics are pretty much intelligible because the vocals are all inhuman shrieks.
Anal Cunt was much the same when they covered things like MC Hammer's "U Can't Touch This" and commercial jingles... in the typical, lye-gargling, a-thousand-dying-tyrannosaurs shrieking, billion-guitars-being-smashed style of Anal Cunt.
"The Crow Man", a rather upbeat, folksy-sounding tune by Pagan Altar, about renewing the earth every year via human sacrifice.
Used "Play With Me" by Extreme. Rather than being upbeat with dark lyrics, it gives us some of the most ridiculously dark riffs in history, and puts it to lyrics like:
Ring around the rosie//
Red light, green light//
G.I. Joes and Barbies
Doom Metal band Sentenced are practically the embodiment of this trope. The music is very upbeat, catchy and joyful yet the lyrics are almost always about suicide. 'Excuse me while I kill myself' for example is about blowing your brains out, yet the song is quite catchy.
"Let The New Day Begin" by the Swedish death/power metal band Therion from their early (before they shifted to powermetal) album Lepaca Kliffoth. The music is fairly typical death metal with a bit of early power metal, while the lyrics basically amount to a message of perseverance and greatness of Man. The final verse goes like this:
Join with the fallen ones/Open your eyes and see/There is no pain to fear/Your strength will carry you/And when the sky turns black/Gaze through eternity/To stars so far away/But trust me, they can be reached/
Type O Negative loves to do this, from "We Hate Everyone" being sung deliberately in a dispassionate way to the upbeatness of "Dead Again."
You'd think Shai Hulud's "Misanthropy Pure" would be about killing all humans painfully in a sea of gore, but the singer shouts what's essentially a treatise on not giving into the iniquity that plagues man, to be tolerant, and to use hatred not to purely lash out at everyone, but to fight against injustice.
Steel Panther is a novelty band whose lyrics are based on cartoonishly overblown misogyny - think Anal Cunt's take on the same subject matter turned down from 11 to about 7. "Community Property" is a ballad, the chorus of which is "my heart belongs to you/but my cock is community property".
"Run To The Hills" by Iron Maiden is a very epic, uplifting song about the genocide of Native Americans.
Flight of Icarus at first seems like an uplifting song about flying. However the title actually refers to a tragedy.
Yeah, fly on your way like an eagle
Fly as high as the sun
A very jarring example comes from the German band J.B.O., which specializes in parodies and metallized covers of songs. Their song "Gänseblümchen", translates as "Daisy", is about a guy singing a love song to a girl. This includes writing poetry and picking up flowers, done in Heavy Metal. In the third verse the music abruptly switches to a softer style and the singer goes on how he will torture the girl if she leaves him. Since it is sung in German it sounds doubly menacing. Can be found here
Another hillarious example from J.B.O. is their cover of Nicole's "Ein bisschen Frieden" (a bit of peace). Nicole's song is a lighthearted song about a girl dreaming of worldpeace. J.B.O.'s cover uses exactly the same lyrics, but is a extra heavy and edgy song that sounds similar to the harder songs of Rammsteinnote so similar that the song is often credited to Rammstein and Rammstein's manager even sued them. It contains further some samples of shrieking children and machine-gun fire. here a link.
Many songs by Knorkator take the same route. "Hardcore" is probably one of their most quiet songs that nontheless is about super-loud music, while "Du bist so still" (you're so quiet) is the exact opposite.
"With a little help from my friends" is a Black Metal parody, but if you can make out the words its actually a motivational song about friendship and true love. On the other hand, their "Christmas Rant" sounds like an actual christmas song but is probably the most angry and frustrated of their songs, which doesn't really seem to be for laughs but meant in earnest.
Judas Priest's "Painkiller" is an immensely heavy metal song which could rival the very dark "Master of Puppets"... and it talks about a savior who helps mankind survive and basically ensures a happy ending. Halford screaming the vocals in a pretty insane tone probably doesn't help.
At first glance, Mötley Crüe's "You're All I Need" is a pretty straightforward power ballad which tells the endearing story of a young man and his girlfriend... take a closer look at the lyrics and it becomes obvious that it's about a man killing his girlfriend out of jealousy. "Laid out cold, now we're both alone, but killing you helped me keep you at home."
"Kickstart My Heart," an upbeat metal tune... about Nikki Sixx being clinically dead for a minute after overdosing.
Witchfynde's "Heartbeat" sounds like a typical 80's power ballad if you aren't listening too hard; the chorus is "(she said) Can you feel my heart beat? It's beating for you..." However if you pay attention to the lyrics, the song is actually about a female vampire that preys on lonely men.
Black Sabbath's "NIB" subverts this — it starts off sounding awfully sinister for an apparent love song... but once you get to the lines that imply mind control and reveal that the singer's character is Lucifer, it all comes together.
In fact, a fair bit of Black Sabbath's output has an underlying positive message. "Children of the Grave" and "Never Say Die" also suit the trope.
Metallica's "Wherever I May Roam" is a typical metal ballad, but the lyrics are about vagrancy and would fit more into a country song. Doesn't stop the song from being awesome, though. Word of God says it's about homesickness.
"One" is this way as well, or at least at the beginning. It starts out so light and, to someone, even soothing. Guess whatit's about?. A soldier that loses all of his limbs, his eyesight, his hearing, and his speech due to a landmine. His mind still functions perfectly which means he is literally a prisoner in his own brain. At least it gets heavy near the end but the beginning can be misleading.
Metallica's cover of "Die, Die My Darling", originally by The Misfits, is a song most people can't help but rock out to, and then you hear the lyrics. At least the name gives you a hint about the song.
"Fade To Black" is a song with a sad melody and lyrics that might as well be a suicide note. It isn't, however. James Hetfield has stated it's about a some Marshall Amps that were stolen from him during a tour. Yes, it's a suicidal song about some stolen Amps.
"The Unforgiven", all three versions sort of qualify too, especially when you hear them in the order of release right after each other. The first is a heavy song about someone who can't forgive someone else, the second is another heavy song about someone else who can't be forgiven, and the third, which starts with a beautiful piano-solo and ends with a heavy guitar-solo, is about someone who can't forgive himself for whatever he may have done.
"Enter Sandman" is a Thrash Metal song with the lyrics of a lullaby... And it's one of the most famous Metallica songs of all time.
Megadeth's Chosen Ones is a very technical thrash song, but is about the killer rabbit from Monty Python And The Holy Grail. "For death surely awaits you with sharp and pointy teeth!"
Dog Fashion Disco did this a bunch, most memorably on "Pogo the Clown," a jazzy rock song about serial killer John Wayne Gacy. DFD's singer later wrote "Chloroform Girl," and acoustic song about a kidnapped sex slave who's "only alive because I like you," and is working on a solo project dedicated exclusively to these kinds of songs.
One of the most popular songs of the german band "Die Apokalyptischen Reiter", "Die Sonne Scheint" has probably the most upbeat lyrics ever heared in Metal. Neither the melody nor the the video suggests this.
The Swedish band Ghost lives this trope. They play catchy, melodious '70s rock... with over-the-top Satanic lyrics.
"Vide Infra" by Killswitch Engage is a loud aggressive metalcore song that is filled with harshly screamed vocals and thick and pounding guitars. But lyrically the song is about preaching equality, tolerance and respect to people different then you.
Used for comedic value by Psychostick whose metal-tinged modern hardcore sound is used as a vehicle for them to bitch about (as well as other things) very mundane and silly topics such as itchy balls ("Scrotal Torment"), a piece of shit car ("Two Ton Paperweight"), and how much they hate doing laundry ("I Hate Doing Laundry").
"This is More" by Stick to Your Guns. The vocalist sings "rest assure that with a heart that's pure, we'll be victorious and not let our hate get the best of us"... over a brutal breakdown.
Much of their music, for that matter. Not helped by the fact that the singer tells short, inspirational anecdotes between songs live, and that the newest album is called "The Hope Devision", and has a heart as the album art.
The hardcore punk band 25 ta Life love this trope. Not only do their heavy and aggressive sound and hip hoppish bravado conflict with their lyrics, but their lyrics conflict with their lyrics. The band intersperses hip hoppish use of "motherfucker" while extolling the virtues of friendship, brotherhood, etc.
An inversion of most of the examples on this page: In This Moment are known for Maria Brink's Metal Screams, and although she usually adopts clean vocals and softer tunes for her more upbeat songs, sometimes she doesn't. "He Said Eternity" sounds decidedly odd sung in a death growl.
Deathcore band Despised Icon have moments of this, such as their song "A Fractured Hand" which features lyrics like "If only I could look at you again with the same eyes that once cherished every single step you took/My heart aches whenever I think of that night you fervently whispered 'je ne te connais plus'/This is the end of something beautiful".
Some songs by DragonForce arguably fall under this in a weird way: not only does the music (generally upbeat, fast, and even uplifting) disagree with the lyrics, but the lyrics don't always agree amongst themselves. "My Spirit Will Go On", in particular, has both a catchy tune and extremely depressing lyrics that suddenly get contradicted by the final line of the chorus. See also: "Black Winter Night", which is a triumphant-sounding tune (complete with brass section) about sailing on endless seas of sadness as the world ends and all of humanity dies out. Then again, the band has implied that they write their lyrics based on the Rule of Cool, so...
"My Spirit Will Go On" has the darkest intro of any of their songs.
"Disciples of Babylon" is their only song that doesn't directly imply the inevitable death (usually in a war that apparently lasts forever) of the protagonists. What the song is about instead is a matter of heated debate.
In a less severe version of this trope, all of their songs are set in winter, usually during a snowstorm, despite their style being summery. They also tend to be set at night, and usually while waiting for a "brighter day" that never seems to come.
Several songs from the album Ultra Beatdown also qualify in a big way:
"Heartbreak Armageddon" is about a man who spirals into depression after being divorced.
"Reasons to Live" is at a counselor who fails to prevent suicide.
"Scars of Yesterday" qualifies as the big one here — when you look at the lyrics, it's quite clearly about rape.
"Blood Religion" by Gamma Ray is a song about a vampire. It starts out with dark sounding music while Kai Hansen sings about his soul being in Hell for eternity. Then he screams "Yeah! Bite me!" and the music becomes upbeat (for metal) and catchy, but the lyrics are still creepy, if pretty cheesy. When performed live, it ends with an audience sing-along about "screaming for blood red vengeance."
Sonata Arctica has its fair share of melancholic love songs played to the fast, upbeat bombast of power metal.
It also has "The End of This Chapter" which sounds mostly like a power ballad, has most of the lyrics of a melancholic love song, but is actually about a stalker.
Probably the most impressive is "White Pearl, Black Oceans", another song that's mostly a power ballad, about a lighthouse attendant hooking up with a girl at a party the night before she sails away, getting knocked unconscious by her jealous husband, and then her ship crashing and everybody on board dying because he wasn't there to work the lighthouse.
And "Shy," which is sung in an adorably well... shy voice but is basically about the singer stalking his crush.
Without filling three screens full of examples it's easy to say most of Sonata Arctica's pre-Unia stuff is actually pretty creepy if you listen to the lyrics but on the surface is the audible equivalent of an explosion in a skittle factory.
Nightwish has a few songs that come to mind. First is "Feel For You" off of 2002's Century Child. What ostensibly seems to be a love song, starts growing grim, and once you hear the male vocal, you realize it's about a murdered ex, an unhealthy obsession, or both.
Barely cold in her grave
Barely warm in my bed
Settling for a draw tonight
Puppet girl, your strings are mine
Another is "Eramaan Viimeinen". This is a very upbeat song with guest vocals from Jonsu, lead songer of cheery pop/rock band Indica- with depressing lyrics about wandering the wilderness alone.
Wintersun has several of these. Most of the songs are speedy, energetic, and sound uplifting. Then you read the lyrics: "Nothing but blood so red and deceased / Nothing but pain, I fall on my knees / Tormenting demons, I suffer and bleed / Only way out is through window of dreams"
Axenstar's "Northern Sky" (he sings it like he's going on an evening stroll) includes the lyrics
The rain and thunder came crashing down from heaven Storm winds are blowing like hurricanes of madness Earthquakes are shaking the core of the planet Volcanoes erupting and fire spreads across the sky
Helloween has "Star Invasion". It sounds like a near-epic and entirely serious ballad, with cool solo, not unlike e.g. "Why?". Even after 1008 Screwy Squirrels teleport in.
Alestorm's cover of the Stan Rogers song Barrett's Privateers falls under this. It's a lively, energetic, incredibly fun song to listen to...until you actually start listening to lyrics like "Barrett was smashed like a bowl of eggs, and the main trunk carried off both my legs". And let's not forget the last verse, and the chorus:
So here I lay in my twenty-third year
It's been six years since we sailed away
And I just made Halifax yesterday
God damn them all, I was told we'd cruise the seas for American gold
We'd fire no guns, shed no tears
Now I'm a broken man on a Halifax pier
The last of Barrett's privateers
The original song was much more fitting with its lyrics.
Theocracy's "Light Of The World" has a very triumphant sound (complete with epic key change near the end) but the chorus "We are the light of the world, we say, but we've blown out our candles and left men for dead singing 'we are the light of the world today' as the darkness descends on us all" pretty much go to show how people of the Christian religion have cowered away from showing their faith.
Price of a Mile and Cliffs of Gallipoli are both badass, upbeat songs about the senseless death of World War I.
The champion example is The Final Solution, a ballad about the Holocaust, that the band now refuses to play, because they found it unsettling to see the audience cheer and headbang along to it.
The ending to Protest The Hero's "Turn Soonest To The Sea" has a Disneyesque sing-song group chorus with the following lyrics:
Maybe someday when, when this bloody skull has dried (I'll) know our city is in ruins When our greatest source of pride (is) a monument of dicks and ribs and the gender crown we wore Where underneath, a plaque will read, a plaque will read, "No woman is a whore"
Justified, in that it's about tearing down our society's entrenched unfairness and creating a world of true gender equality, but still pretty jarring the first time you hear it, when you haven't had a chance to figure that out.
Dream Theater has utilized the "death growl" vocal effect exactly once: on "A Nightmare To Remember", it occurs after the HAPPIEST part of the story where it is revealed that everyone survived a car accident. This part is, for some strange reason, very angrily shouted.
It's a miracle he lived
It's a blessing no one died
By the grace of God above
Don't forget Solitary Shell and About to Crash, both of which are movements in the song "Six Degrees of Inner Turbulence". The entire song is about mental illness, and these two movements are uplifting and happy. Like this little dity, set to perfectly happy sounding music:
She was raised in a small midwestern town
By a charming and eccentric loving father
She was praised as the perfect teenage girl
And everyone thought highly of her
And she tried everyday
With endless drive
To make the grade
Then one day
She woke up to find
The perfect girl
Had lost her mind
The Rage Against the Machine cover of Devo's "Beautiful World" is an inversion—the Devo version is upbeat and happy-sounding—as are the lyrics up until the last line, which puts the whole thing in a different light. The RATM version, surprisingly, is somber throughout.
The French band Carnival in Coal experimented heavily with this, in both directions. For example, turning '80s pop into death metal, or making "a Jamiroquai-esque disco tune with gore lyrics".
The Finnish band Finntroll. Several of their songs have a rather upbeat tune, yet the lyrics are always about trolls devouring humans and burning churches, how great it is to live in a dark icy land with no "human-pest" around, or generally filled with dark imagery of cursed forests and evil spirits.