Will you use some kind of Flash audio compression ( Like YouTube did with videos (FLV) ) ? It would be better if you did tough. Because some people use slow internet connections.
Well, as long as it concerns music streaming, FLV compression isn't really useful, for most people have fast enough internet connections to listen to the music continuously, and they might not want to lose quality. It may be worth creating a poll though.
By the way, I'd like to know what people exactly want: a single player with the whole playlist, or a player for each file? Or maybe one player per game?
You mean that if you already have the song downloaded that you can play it from your computer ? This would be possible with PHP i think. But the problem is where do you need to find the music file. It's best if there's an option "Play from my computer" where you can select the music file.