Tools for Managing Large MP3 Libraries?

Daniel Drucker asks "My MP3 collection is growing very large (>40gb), and it is becoming apparent that I cannot continue to manage it by hand. I'm looking for a tool which would, ideally, have every song in a (e.g.) MySQL database, be able to rename incoming songs to a consistant format, and do other tasks associated with a big music library. I'd love to use Perl for this, and am planning on doing some serious coding in a few days, but before I start I'd like to know if anyone has seen or done something like this."