it might have been...
I know there are lots of shoutcast mods that allow functionalitly similar to this...
The biggest problem with streaming music is...even if your stream is at a meager (and shitty sounding) 56kbps that means that on a connection like cable, you can support like 8 users and your upstream is maxed out...if youre doing it from a webserver you pay for, youd go through so much bandwidth it would kill you...
it would be something to look into for personal use tho
I ran a shoutcast server off a crappy laptop in my corner for a while and it was cool, I had a very basic web interface that showed what was currently playing, and what was next and stuff like that...
The only think I can think of that would most likely prevent this from working is that shoutcast, and any other form of streaming music for that matter, would have to have a separate instance running for each user so that it could play x-amount of different songs simulatneously...
of course, if this was just for one user, IE, you...it wouldnt be a problem, and it would be less illegal because you could claim it was your private music colletion...password protect it or something...not to mention that your stream bitrate could be a lot higher if you only had one user to support...