I realize this community has been inactive for ages, but I've only recently come across KLuJe, an I quite like it. I've written a patch that supports automatic music detection from JuK. In case anyone is interested, I've made a source package and put it up on the web: KLuJe with music detection
If anyone is interested in resurrecting this project properly I'd be very happy to help. For now just enjoy the automatic music detection!