You’ve heard of the Human Genome Project. This site’s founders do something like that but with the “Music Genome Project.” They’ve analyzed the nuances of things like melody, harmony, arrangement and rhythm on more than 400,000 songs. They pair them up with songs you already know, creating personal radio stations. Plugging in “Beck,” for example, took me from him to Belle & Sebastian to The Microphones to Elliott Smith and back to Beck. Info about the song, album and artist pops up with each song. Skip songs you don’t like, and bookmark ones you do. There’s no downloading, but you can link to iTunes or to buy songs. Or just let it play on your computer and discover new music you’re almost guaranteed to like.