Tired of listening to all the political commercials on your radio station at work? Looking to find some new artists or a new sound? Interested in seeing scientific concepts applied to musical content? Bored and feel like playing with something for free on the Internet?
Look no further than Pandora.
Some folks got together and started the Music Genome Project, cataloging the songs of over 10,000 artists by such things as major key tonality, repetitive melodic phrasing, and--my favorite "gene" so far--extensive vamping (that's one of the genes on my Sting radio station). You can guide their program by giving a thumbs up or thumbs down to the selections they make based on common "genetic" elements. Sometimes the program gives you a golden, perfect station complete with artists you've never heard of before but will be hunting for on Amazon. Sometimes the program takes a turn into WTF-land and your thumbing down selection after selection.
But, hey, it's free and pretty interesting. Give it a whirl.