Delete songs and other content in iTunes on Mac
In the iTunes app
on your Mac, choose an option (Music or Films, for example) from the pop-up menu at the top left, then click Library.
Click the item to select it, then press the Delete key.
Click Delete [item].
Do one of the following:
Remove the item only from your iTunes library: Click Keep File.
Delete the item from your computer: Click Move to Trash. The item is removed the next time you empty the Trash.
Deleting an item from a playlist doesn’t remove it from your iTunes library or your computer. Deleting a playlist or folder doesn’t remove the songs in it from your library or computer. Deleting a folder removes all the playlists and folders inside that folder.
If you subscribe to Apple Music or iTunes Match, songs you delete from your iTunes library can still be available from iCloud, so you can play or download them anytime.
If you can’t remove a song, make sure you didn’t select a song in a Smart Playlist with “Live updating” turned on.