Ripping CDs in Windows Media Player - Music Brainz?

Hmm... I ripped a *lot* of CDs this week. Windows Media Player did a great job. However, I've got a handful of CDs that didn't have track information available. Some discs simply could not be identified. Some errored out, some ripped but with "unknown" artist/album/track info.

I'm probably going to see if I can give Banshee a chance with Music Brainz on those discs. I doubt I'll re-rip my whole collection, but I suppose that's one step closer to freedom. Does anyone know how MusicBrains actually works?