Hi, I'm the software developer behind http://jthink.net/songkong an automated music tagger available for Macs. SongKong is a music organization and tagger application designed to simplify the task of managing your digital music collection. If you have ever used Tuneup Media or Rinse My Music you could consider SongKong as an alternative. The major differences are that: SongKong does not run within iTunes, however it can still keep your iTunes database in sync. SongKong uses MusicBrainz and Discogs instead of Gracenote database SongKong creates very detailed reports showing exactly what is had modified, example here SongKong keep all changes in a database so you can revert any changes you don't like at a later date. SongKong includes fixing metadata, fixing artwork and deleting duplicates within a single application with one lifetime license. SongKong can be used on folders, files, playlists or your whole collection SongKong can be used to monitor a folder and automatically fix new music as it is added to this folder. SongKong is created by one person, we have open discussion forums, and an an open bug tracker as well as email support, see here The free trial can be used as many songs as you like for as long as you like and it will create a report showing exactly what has been matched and what could be modified but it doesn't actually save the changes unless you have a full license.