Lux Aeterna: string quartet.
Originally from Requiem for a Dream, but has been used in the LOTR: The Two Towers, as a movie soundtrack. Though not actually used in these movies, this song was used in the trailers for: 24: Redemption, Babylon A.D., I Am Legend, 300, The Da Vinci Code, and a few others…one of the Final Fantasy movies? It’s kiiiiinda done to death, but understandably, since it’s a beautiful and dramatic song.
Electric guitar version VERY GOOD!
GMS Juice Remix : Those of you into goa trance would like this version of the track. :) If you don’t have the patience for the long buildup of this song, FFW to 2:36 and listen to the digitalized version of the melody.