people have been creating 140 character music pieces in the supercollider music language for a while. its very tricky to make something that lasts and evolves and has structure and keeps your interest.

here are some great ones:

http://fredrikolofsson.com/f0blog/?q=node/478

play{a=SinOscFB;sum({|i|a.ar(a.ar(a.ar(a.ar(i+1,1/9,999),1/9,a.ar(1/9,1,1/9)),a.ar(0.1,3),i+2999),a.ar(1/9,1/9),1/9)}!9)!2}//#SuperCollider

r{loop{x={GVerb.ar(MoogFF.ar(ClipNoise.ar0.4,LFPar.kr({0.3.rand}!2,0,600,990)),9,9,1)}.play(s,0,19);3.wait;x.release}}.play//#SuperCollider

audio examples on the page above