Duplicate listings in Music Library but NOT duplicate files

See Duplicate songs in iTunes - Apple Community. You appear to have what I refer to as logical duplicates, two entries in the database pointed at the same physical file. You should delete the newest of these with sending the underlying file to the trash, which leaves the file there for the remaining entry.

See also Move your iTunes library to a new computer - Apple Community in case the easiest solution is to revisit the library migration.

tt2

Hmm. I realise I wrote "with" when I meant to say "without", so apologies for that. You should get a prompt when to delete an item from the library, and that item is located within the currently designated media folder, if you would like to delete the file, or send it to the trash. As long as you answer no then the file should be left in place. If you sort exact duplicates by date added then as long as all the duplicates were created at one time it should be possible to select them, delete without sending anything to the trash, and leave behind the good copies. If the duplicates were created at different times that you might need to work in smaller blocks using the column browser as a filter, e.g. all artists beginning with A, then B etc. so you can scan the selection more carefully before you commit to deleting any entries.

Alternatively, as noted, see Move your iTunes library to a new computer - Apple Community in case the easiest solution is to revisit the library migration. Using this method should not result in any duplication.

Or you can option-start-Music to create a new empty library and import the content if you don't require any of your playlists, ratings, play counts, etc. from the old library. See also Managing your Mac media libraries - Apple Community. If you're going to start over you might as well know where things are expected to live.

tt2

You're welcome. 🙂

tt2