I have been working on music and sound for "virtual" sculptures, all in Second Life. It's been quite exciting, mainly due to specific barriers to music production inside the world. 1) Samples are limited to 10 seconds. 2) Manipulation of the sound itself (pitch, length, etc) must be done outside Second Life; samples can only be played in-world. 3) As a rule, a sound can be triggered by a script in the sculpture, but they can't be "stacked", ie you can't play the sound, then play another sound over it to make harmony - the first sound will stop. 4) It's fine to loop sounds, but it starts to sound like a broken record. More later.
Tim Risher's little blog