My MP3 collection / iTunes library is moderately poorly tagged.
I have tried all kinds of automatic tagging tools in my day with very limited successes. MusicBrainz in its original incarnation was useless for my needs. I could name all the rest, but why, since hardly any of them work well.
The other day my brother Kevin mentioned a new alpha-stage product from them called Picard. From their overview:
Picard is the next generation tagger that will soon completely replace the classic MusicBrainz Tagger. Picard is an album oriented browser (as opposed to track oriented) and thus works quite a bit different than the old tagger. The 0.6 release of Picard does not make use of any fancy track lookup schemes like acoustic fingerprinting or text index look-ups. Even though Picard does not support these features, some users find they can tag music files faster with Picard than with the old acoustic fingerprinting tagger.
I have been using it for about two weeks now. The software itself is still really buggy, it crashes constantly, but I can see where they are going with it and I like it. One of the keys is the quality of the MusicBrainz album database, and it is quite good, although it lacks album art most of the time and definitely isn’t the best database out there, allmusic.com has consistently better data. And the search is quirky, doing things like searching for collaboration albums (“Calexico and Iron & Wine”) or misspelled titles is hard. But when it works it is wonderful.
iTunes isn’t making it any easier on me, since I have to remove the albums from the library, tag them and then re-import, which means losing all my rating and playcount information.
But at least now, before I import anything I run it through Picard first.