From the people that brought you the music genome project which analyzes a song for it’s musical components instead of assigning a genre, comes Pandora’s box. Pandora is another music radio type site that you type in a band and they begin to find songs you might like. But instead of linking Poison to say 80s hair music, the site breaks down the music to it’s components, like:
Poison – Subtle use of voice harmony, overpowering drums, strong electric guitar solos.
So basically you are getting to the core of the music you like. And as the other websites, the more your rank as like and dislike, the better sense the site has as to what you enjoy musically. Very easy to understand site. Also offers a subscription based service, if you have the home electronics to support it. But if you are just listening on the web it’s free.