Are you familiar with "Pandora"?
It's a free on-line music-streaming service from the good folks at the Music Genome Project.
Their goal is to analyze music by its components and elements of style, and to help people find new music to enjoy by extrapolating from their current tastes.
For example, if you go to Pandora and search for, say, the Oriole Four, it will start playing lots of barbershop music for you!
Pandora.com; it's free, fun, and musically educational!