This seems to be working pretty well.. Better than the current system for sure, but it seems that in some cases (if new system was to be applied), certain bands need a personal approach to get the most similar artists. Maybe it is something that you could fix, I don't know. Anyway, it is a great idea in general and should really get out in the open. Maybe you should try to explain the concept a little bit shorter, so that the long text wouldn't scare away the potential readers ;)
You're doing a great job here. I think it's a nice idea as well, but the tags might be a problem - as you self said. I mean, some people really abuse these tags - that should be adjustest then somehow.
Thumbs up, it's really well thought so far.