The only way I can think of to find new bands that you like that is to compare them to bands that you currently like. That obviously doesn't help a lot when you have eclectic tastes, but I think you're just going to be out on your own there.

Secondly, simply comparing keywords doesn't work. While it's hard to separate Pearl Jam and Creed based on keywords alone, there are many people who like one and not the other. And the only way I can think of to solve that is to base the suggestions for one user off the likes of other users.

But then you fall into the problem of not already being popular. If there's some band out there (let's call them UndergroundBand) that's not yet popular, but, if they heard them, virtually all fans of PopularBand would like, but only 1% of those fans had heard them at all, then you fall into the same trap as you currently have without some sort of promotion tool.

It seems to me that the way you'd have to do it is to have ratings for all the bands from each user, both positive and negative. And I think I'd classify them that way. Not just one star to ten stars, but negative five to positive 5. And make sure to keep in an "I haven't voted for this band" flag so that that result won't have any effect. That way, if you take all the PopularBand fans and see that of those that voted for them, UndergroundBand has a rating of 4.5, then the fact that they're unknown wouldn't be an issue.

And the site can't only promote the bands they have. They need to have all bands in their database.

I know that this isn't really a new set of ideas, but I think it's important to point out that there an unquantifiable quality that permeates things that people like that can't be determined by a computer. And it works both ways. Some people only like what I would consider shlock and I'm sure that those people think that what I like is shlock, even within the same genres, so you can't just apply some arbitary "quality" criterion, either. Maybe some sort of "pretentiousness" scale.

Also, I'd like to see why I've been recommended an artist. What was the suggestion based on.

Like I said, none of this is really new. Amazon does stuff like this, but it doesn't really seem to work with music on their site.