As a musician, I'll say it's an alright idea, although not overly original. I wouldn't really join it if I just happened to come across it.

As a web developer, I'll say you've got a lot of work to do. It looks EXACTLY like 553 million other forums out there, and offers little valuable content.

Get some musicians to start writing articles, posting tutorials on instrument setups, posting more mp3s of original artist...make me WANT TO USE IT!