'GLaDOS's Song', a Cut Song written by Ellen McLain herself with her husband John Patrick Lowrie playing guitar.

Despite the digital effects and the nigh-incomprehensable lyrics (they're in Latin, for the curious), the sheer emotion in GLaDOS' singing is enough to make you want to shed a tear. This song only plays on the title screen while you're in the old Aperture Science testing spheres, but it's one of the most haunting, etherial melodies in the entire game.

And during the game you can find some of these turrets singing 'Turret Wife Serenade'.

There's something about the music box version of the turret opera that just drives you to tears.

Some humans did it in a capella, and it's pretty damn good!.

Before the end song, the player is greeted with a choir of turrets.

Now available in acapella, courtesy of Peter Hollens and Mystery Guitar Man.

Like 'Still Alive', it sounds better in a minor key.

The ending song, 'Want You Gone', (spoilers, of course) is really good.

It sounds so sad and lonely, it's impossible not to feel bad. It's a remix of I Made It All Up, but it has elements of Cara Mia Addio and Wheatley's leitmotif mixed in.

If that didn't make you cry, listen to Space Phase, the menu theme that plays after beating the game. Spaaaaace : short, incredibly sad for those who finish, and feeling just so empty.and the second half, a slower reprise of 'Wheatley Science', pumps you up in preparation for one hell of a Final Boss battle that places the weight of all of Aperture on your shoulders. Omg, What Has He Done? The first half of the song leaves you feeling terrified at how wrecked Aperture has become.Your Precious Moon, the music that plays when Chell fires the Moon-portal.even though something good happens instead. Even without knowing the context of the song, you can just feel that something bad is going to happen about half-way through. Bonus points for the ending of the track sounding more frantic and erratic than usual, mirroring Johnsons descent into insanity. It really gives the impression that something human has turned robotic. During the '50s chambers, the music starts out with natural instruments, but starting around the '70s, synth starts replacing the instruments, and by the time you get to the '80s, there isn't anything natural left, it's all synthetic. What's even more interesting is how 'Music of the Spheres' evolves as you progress through Old Aperture. Then, at 1:07, the music peaks, sounding both ominous and suspenseful. It starts out soft, encapsulating the wonder the player feels looking up at those titanic, abandoned testing spheres. 'Music of the Spheres' serves as the leitmotif of Cave Johnson's Aperture.Vitrification Order, You Are Not Part Of The Control Group and Forwarding The Cause Of Science all count on their own, but they all become even better when you listen to them all together and see how the first two build on each other to create the third, and then combine with another track ( Music Of The Spheres ) to create The Reunion, arguably one of the best pieces in the game.The Friendly Faith Plate is an has a catchy beat and accompanies the electronic sounds of the Faith Plate sending you careening through the air.And it's as awesome as you imagined it would be. With the release of the first volume of the official soundtrack, we now have The Courtesy Call from the opening without the voice over.What's awesome is how it starts out calm, then grows in intensity at 'Please press the Stalemate Resolution Button', and then goes freaking nuts after the Booby Trap goes off. 'Don't Do It' is played twice, first during the confrontation with GLaDOS, and again at the analogous spot in the Final Boss battle.Cave Johnson plays during the teaser trailers, and it's a triumphant-sounding theme that fits the charisma of Cave Johnson proudly displaying various features of the game as Aperture Science products.Bombs for Throwing at You, Wheatley's final boss theme, is like 'You Can't Escape, You Know', GLaDOS's final boss theme from the original, except it is faster, more frantic, and has some of Wheatley's Leitmotif mixed in at some points.'An Accent Beyond', a fast paced tune that kicks in once Wheatley starts frantically escorting you away from GLaDOS's grasp.'You Know Her?' is a fittingly ominous track for GLaDOS waking up, killing Wheatley and throwing you into the incinerator.'I AM NOT A MORON!' starts off as a cheery electronic theme that turns into pure orchestrated awesome.

Plays in one of the tensest moments of the game. The Part Where He Kills You is basically Portal 2's '4,000 Degrees Kelvin'.Which is a remix of nothing else other than.

Portal and portal 2 soundtrack