YouPhonics certainly sounds like a good idea, capturing the "social" aspect of GitHub. I assume it allows you to mash-up and remix peoples tracks? That would be killer, and I'm sure people using services such as SoundCloud[2] to host their tracks would quickly migrate to it. (If you have the time, post an guest login here for us to demo it.)
I second rch's motion[3] to GitHub YouPhonics' code―even if it is ugly and hacky (depending on your level of perfection, whose code isn't?!). If anything, you'd make all the effort you put into it even more fruitful.
[1] http://news.ycombinator.com/item?id=2429930 [2] http://soundcloud.com/ [3] http://news.ycombinator.com/item?id=2430432