Clicking the "Browse" link takes me to "Browse Random Files". First, I don't believe that the uploaded songs should be thought of as "files." People want music, tunes, and tracks. "Files" almost makes me weary of having to download something.
Second, there needs to be some structure to browsing - by artist, genre, year, popularity, etc. Presenting a person with a few random tracks when your database has 1000s of them makes it difficult for users to find anything specific.
On profiles, the url pattern needs some work. You mention in your blog that you would like bands to say "check us out on Tune To Us." However, if they're uploading their songs and want people to hit their profile they'd have to say, "Check us out at Tune To Us slash profile slash view slash 2934." Perhaps adjusting to something shorter with more significance. A band/user should be more than just a number.
I believe your site's has potential, but it also needs some work to make it useful to the masses. Good luck with it. I'll keep an eye on where it goes.