Requiem For A Theme

Thanks to my "fountain of totally useless trivia" I now know the answer to something that has been bothering me for at least 5 (years now.)

What the heck is this song?

Well ladies and gentlemen, as you can see it is from Requiem For A Dream. The only thing is, I've never seen Requiem For A Dream. The only time I've ever heard this song is in movie re-cuts where the editor is trying to be dramatic (succeeding, but evidentially being totally cliche along the way.)

So now I know. If I die tonight, my life is complete.