I have about 50 playlists. In the Library, I have about 3500 songs, many of them duplicates. For example, I have 8 versions of Darn That Dream, most of them identical, some containing small improvements (like adding alternate chords, better layouts etc). I'd like to delete the older versions, but there is no way to find out which playlists (if any) they are used in. A most useful feature would be if I could, say, ctrl-click on a song title to check that. It shouldn't be too difficult? The iTunes app on the Mac has this feature. ForScore too.