That's right, you've pretty much figured it out. There's the basic chord sequence, then there's a thousand or so oscillators which pick a random note in the next chord, and slide towards it. They start at random frequencies at the beginning (and are random halfway between chords), which makes a band of noise. I think I'm going to try and make a version that can be controlled by a MIDI keyboard, because right now, you have to enter a table of frequencies which is a pain in the ass.
Thanks for feedback everyone