Smart duplicates scanner for iTunes.
iDupe is designed to help you remove any duplicate tracks from your iTunes library with an outside scan action. After loading the app, you can select specific tracks in your library and run a scan to detect any duplicates and then take action to remove them, rename them, or check them again. The app offers a number of options for how you treat the duplicates you find; and while the interface is a bit rudimentary, it all works fairly well for removing those dead and extra tracks from your system.
Analyze your music collection, fix your metadata, and build playlists.
Clear iTunes duplicates.
Manage iTunes duplicates.