Okay, most of us have at least heard of chaos theory when it comes to math. It's all about randomness and the unexpected. Chaos music tried to reflect that ordered disorder (or disordered order) rising out of...whatever it arises from. I mean, thermodynamic theory says that systems naturally tend toward disorder, but maybe we don't know what we're looking at. Thank gawd I was a liberal arts major.
Anyway, chaos music didn't go over all that well, except among the '50s beatniks and jazz musicians, but they were mostly stoned most of the time, and they gave us hippies. Somewhat typical of chaos music is the album "Chaos," by Paul Bley, which, interestingly enough, didn't debut until nearly 50 years after chaos music was a thing (on college campuses and New York coffee houses). It's got lots of randomness, though I don't know that it has much in the way of unexpectedness. Still, I dig it, man!
Next time: fractals!