Thank for you the clarification on where the recommendations fell down.

I have resisted letting people upload their record collection because I want to focus on making the site work well when I don't know anything about the user.

Letting users spy on the recommendations of people they admire or feel they are similar to is in the works. Once I get enough users, I plan to have a thing that says, "Hi Jill, your taste is similar to Bill. Would you like to be updated on his recommendations?"

I already pull in the band descriptions from Wikipedia.

Thanks again for the detailed feedback - it's really useful.