Forget all those numbers in Area 51. You're focusing on the wrong thing. When users start quoting numbers and start scheming "traffic-growing" goals, I start to get nervous. The subsequent suggestions are usually counter productive to sustainable, organic growth.
Don't lose sight of the most obvious way to grow this site — provide high-quality content and draw people into your site by becoming the preeminent music Q&A destination. Google and social networking are your friend.(1)
We find that the best way to attract new users to the site is by highlighting your most intriguing questions. People love answering questions, and a particularly interesting and intriguing question is irresistible. It's the quickest, most definitive way to help someone realize "Yeah, this site is for me!"
Use those social bookmarks!
1 Seen this before? Yeah, it's a duplicate of this response. I would have thought this question should be closed as a duplicate, but many responses and comments have already been posted taking off some off directions, so I hope to drive this point home.