I have done the following:
cd /var/lib/mpd/music/WEBRADIO
mkdir Rock Jazz Blues Classical Pop Soft Talk Random\ Radio
mv *Rock*.pls Rock
mv *Classical*.pls Classical
mv *Blues*.pls Blues
mv *Jazz*.pls Jazz
mv *News*.pls Talk
mv *Radio*.pls Random\ Radio

You will still have some more to move by hand but the bulk is moved
*edit* I did not have to use sudo.