Clint Mansell, performed by the Kronos Quartet

If you haven't seen Requiem for a Dream, or you watched most of it with your hands covering your face, you've at least probably heard it. The film's main theme, "Lux Aeterna," which is Latin for "eternal light," was composed by Clint Mansell.

This track has taken on a life of its own outside the movie. Most famously, it was used in the trailer for The Lord of the Rings: The Two Towers. (It kicks in around 1:42.) Maybe Gollum had a drug problem. That would explain the mood swings.

Clint Mansell was the front man of a British punk pop band in the late 80's, which probably served as the perfect training for scoring a drug movie like Requiem for a Dream. Mansell teamed up with Aronofsky for Pi in 1998 and has scored all of his films since.

Aronofsky is hooked on the guy…but this is one addiction that we condone 100%. Aronofsky and Mansell go together like peanut butter and honey, rather than like heroin and Harry Goldfarb's arm. (Too soon?)

Aronofsky recruited the Kronos Quartet to perform the haunting songs. This group, made of three violins and a cello, has worked with artists like Nelly Furtado and Paul McCartney. If Furtado is "like a bird," Requiem's depressing score is like a bird smashing into a window and dying, slowly, while you watch it take its last labored breath.

The score, combined with the movie's dark, kinetic visuals, create the entire mood. And that mood is "omg I'm miserable get me out of here."

Good job, guys. If you need an upbeat palate cleanser, there's a dubstep remix.