How to Find Duplicate Songs in Your Music or iTunes Library
Whether you’re still using iTunes (macOS Mojave and earlier) or you’ve upgraded to the Music app, the instructions are similar. To see all the songs in your music library, including duplicates, you need to be in the right viewing mode.
Open Music and select Songs from the menu bar on the left. (If you’re using iTunes, navigate to the Library pane, select the drop-down menu near the upper-left corner of the screen and select Music > Songs. ) Select File from the top menu bar, then select Library > Show Duplicate Items.
You should now see a list of tracks that iTunes has identified as duplicates. Browse the list to locate and delete the tracks you do not want.
How to Find Exact Duplicates
Lurking in Music/iTunes is a hidden option to search for the exact duplicates of songs. This feature is better to use if you have a large music library and want to make sure that you aren’t deleting songs that are the same title but different versions. This way, any compilation albums that contain duplicates remain intact. From the same Songs pane in Music/iTunes:
Hold the Option key and select File from the menu bar. Select Library > Show Exact Duplicate Items. In the Windows version of iTunes, hold the Shift key and select View from the menu bar. Select Show Exact Duplicate Items.