That sounds like a good idea. It also sounds expensive, in terms of the server required to host that stuff.

How much use would these features actually get? Does Jon find himself in the crosshairs of some publisher's gunsights over ownership/royalty issues? Who is responsible for ensuring that people only post their own compositions? How much advertising are we prepared to live with? Are we willing to get into paid subscriptions and related headaches? And what about Mary-Sue?