foobar2k (Score 1)

I use foobar2000 to manage my collection (about 10k mp3s). It's got a real low memory footprint, easy search, plugins to do just about whatever you want (I believe there's a musicbrainz plugin, but I know there's a freedb plugin, which is similar). Anyway, checkout http://www.foobar2000.org/. Windows only, unfortunately.