I've decided that trying to fall asleep to music only works if the music has no percussion in it.
I was up for two hours last night trying to get to sleep to the tune of Barenaked Ladies. Didn't work.
My friends say Enya produces a soporific effect, but I find that even acoustic guitar can be quite soothing. I recommend the Tengelsen Brothers or Kirby Heyborne or maybe some Robert Francis.
It also helps if the music is very quiet. Ipods are annoying in the fact that you can't turn them down past a certain level (do they WANT your ears to blow out?). When this issue comes up, I tend to only use one ear -- the one that's not against the pillow, if you're a side sleeper like me. Turning your earphones outward, away from your ear canal, can also help muffle the sound.
Of course, this is in the case where listening to music through a speaker is out of the question. I sleep with a roommate, but if you have your own room I'd suggest turning the volume way down on a set of speakers because then there will be a bit of a "distance" effect on the music as well.
P.S. If you use a speaker system to go to sleep, you might wanna try waking up to music as well. Create two playlists, if you can: One for sleeping and one for waking up. As one might expect, it is best to use faster dance tunes in the morning. Best wake-up call, no doubt in my mind. Beats an alarm clock.
Listening to: "Mi Mancherai (Il Postino)" by Josh Groban
Things Happening today: Music 176 part 3 (out of 4... one more to go!), ummm... wednesday.