Song Sergeant for Mac

From LairWare Software:

Don't you hate seeing the same band, album, or song listed multiple times in your library? Song Sergeant intelligently identifies and removes duplicates, renames inconsistently named artists and albums, reunites orphaned song files to your library, and deals with missing song files. Song Sergeant will whip your music library into shape in no time. Song Sergeant is uniquely capable of merging song files together instead of just crudely deleting extras, letting you keep the best song information and best audio quality even if they're from different song files. Among Song Sergeant's unique features, it will choose the best name from inconsistent artists and album titles, will carefully replace instances of unkept songs in playlists with the ones that are kept, preserves "Last Played" dates, and merges play counts. Sensible preset settings which will please most users, but power users can precisely control what is considered a duplicate and what song information and audio data to prefer, either by changing Song Sergeant's rules or by manually selecting what they want to keep. In addition, users can easily preview songs and browse through related track information and artwork in order to ensure that they're keeping exactly what they want in their libraries.