I'm not the biggest Aphex guy in the world so I don't have a lot to work with--but, Selected Ambient Works 85-92 you should check out and the track "Alberto Balsalm" is what brought me to explore Aphex Twin at all.
Yeah..I thought I was being a good little forum member by posting in other electronica
Thanks for the suggestions, unfortunately emusic doesn't have Selected Downbeats Vol. 1.
Though I don't really know anything about music theory, I actually think you can draw many similarities between psytrance and chamber(classical was a time period) music. The tempo/changing melodies/point-counterpoint/accompaniment/......