* ''VideoGame/Left4Dead'''s main tune was a [[https://www.youtube.com/watch?v=UtrSNUJcvJY sorrow filled piece]], that made you realize that many have died from the ZombieApocalypse, wondering if you will be the exception. At the end, when the chopper/APC/boat arrives, the music seems to be shouting "COME ON! YOU CAN DO IT! SHOW THESE ZOMBIES!". Your teammates are being attacked by Hunters, barfed on by Boomers and thrown across the map by Tanks, but you are still getting to the vehicle. The AI director is throwing everything it has at you, but you keep running. Once you get to the vehicle, you feel like you really accomplished something. ''[=L4D2=]''[='=]s main tune sounds like something, really, really horrible happened in the last 5 seconds, and this is the aftermath.
* The Hard Rain rendition of the menu theme. [[https://www.youtube.com/watch?v=F_7C8oN2klY Once you listen to this version, you'll never go back!]]
* The jukebox in ''[=L4D2=]'' not only plays "Re: Your Brains" by Jonathan Coulton, it also spawns a wave of zombies on you. ParanoiaFuel, anyone? Bear in mind, it's not ''that'' the song spawns zombies, it's ''when'' the song spawns zombies:
-->I think I speak for all of us when I say I understand \\
Why you folks might hesitate to submit to our demands... \\
But here's an FYI: \\
You're all gonna die screaming! ''(cue zombie swarm)''
* ''[=L4D2=]''[='s=] version of the [[https://www.youtube.com/watch?v=IA9totuk3fU Skin on Our Teeth]] music mentioned above. The second that badass track starts you feel like if you don't haul ass NOW some completely gruesome and epic thing will happen to you, as opposed to ''[=L4D1=]''[='s=] version that seems to go: "You can do it!" The first version tells you that you can escape. The second version tells you that if you don't get out of there now, you are dead. And there are several hundred zombies in your way.
* What could beat the [[https://www.youtube.com/watch?v=Qiob3F1NIX4 Tank Theme]]? Why, it would be the [[https://www.youtube.com/watch?v=hk6n1o0YheM Midnight Riders Tank Theme]]. Not to mention Xenogenocides unoffical [[https://youtu.be/Xh0FjIevAnw Metal Tank.]] And the [[https://www.youtube.com/watch?v=I00FXQUgtDM other Midnight Riders Tank Theme]]. In 2020, Xenogenocide's metal version was made official for the ''[=L4D2=]'' Last Stand campaign's final Tank battle.
* Ladies and gentlemen, the song from the Zombie Survival Guide trailer for ''Left 4 Dead 2'': [[https://www.youtube.com/watch?v=iAjCUCnoijc Chocolate Helicopter.]]
* ''Left 4 Dead 2'' features several different versions of the Horde theme for each campaign, mixing the frantic drumming with unique instrumentals to fit with the setting and theme of the campaigns:
** [[https://www.youtube.com/watch?v=0mxDpf70TL8 Dead Center's Horde theme]] uses a fast-paced banjo that makes encounters with the Horde feel more hectic and chaotic than they already are.
** [[https://www.youtube.com/watch?v=YJQeXGys2ys&t=22s The Passing's Horde theme]] uses a frenzied Jazz Organ that fits with the campaign's nightlife theme while also sounding like a ''very pissed off'' monster is chasing you at night.
** [[https://www.youtube.com/watch?v=k4W2Gto63R0 Dark Carnival's Horde theme]] could be summed up as twisted carousel music, with the drumming mixed with a theremin to create a surreal, anxiety-inducing feeling to encounters with the Horde.
** [[https://www.youtube.com/watch?v=ZYNGymXoArw Swamp Fever's Horde theme]] mixes in some truly frantic violins that perfectly matches the bayou setting while creating a feeling of desperation to the Horde encounters. The most panic-inducing theme by far.
** [[https://www.youtube.com/watch?v=3IktN4EF1S4 Hard Rain's Horde theme]] uses a Dobro guitar and a harmonica that gives a much more aggressive feeling that perfectly fits the already intense campaign.
** [[https://www.youtube.com/watch?v=VU0Q82oTDoo&t=15s The Parish's Horde theme]] uses a frantic trumpet that makes it sounds like you're in a surprisingly fun mad dash as you slash and shoot your way through -- exactly what most Horde encounters are. And in the Parish, the final level is a bridge filled with zombies, fun mad dash indeed.
* While it's completely different from every other song, [[https://www.youtube.com/watch?v=b7vQTe-p92M Save me some Sugar]] from The Passing is a nice love song... or not, as it's a BreakupSong - specifically, one belonging to the category of "I Have To Go/It's Me Not You". No wonder the Witch Bride gets really angry if you play on her wedding day.
* The Parish's [[https://www.youtube.com/watch?v=_6n6xWPcIhg version of the menu theme]] deserves a mention.
* Even though it's less than ten seconds long, [[https://www.youtube.com/watch?v=ehhfn9yimj4 The Monsters Without]] is a perfect song for reaching a safe room, especially if your team - or whoever's left on it - barely manages to limp their way inside ahead of the zombies. ''[=L4D2=]'''s [[https://www.youtube.com/watch?v=jR12dzkTVdg version]] is equally as awesome.
* The pre-level saferoom music is a subdued piece of awesome music, giving a safe, relaxed mood mixed with feelings of preparation and anticipation of the zombie-filled path outside. In ''Left 4 Dead'', it's slightly different for each campaign; in ''Left 4 Dead 2'', it isn't - with the exception of ''The Passing'', in which it's a mix of both games' songs.
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