When I tried Composer the other day, I especially liked the approach they took on collaboration between musicians. They really seem to think of it like working with repositories when it comes to managing input from different sources and keeping track of revisions etc.
So maybe there’s is github for musicians in the making, or at least there should be. What they really should do is, is provide an environment to share and collaborate on music/audio data, coming from any digital music production environment such as protools, Logic, Cubase, Ableton or any audio editing solution like Audition etc.
Obviously, it would be necessary to enable playback of any audio format and at least allow basic meta data to be reviewed on any project files from any system to make this a worth while effort. If one for instance could review takes, mixes and things like that with realtime controls to enable/disable revisions to let the differences really stand out… that would be quite a tool for creative professionals.
Update: Apple tried something like this in a limited capacity for videos with Final Cut Pro Server, but it was kind of a flop and the product died after only 3 years…