Q: This ought to be an easy question, I’d think: How can I quickly erase all duplicate songs from my iTunes library?
A: iTunes has a way to identify potential duplicate tracks in your library. Just select “Show Duplicate Songs” from iTunes’ “Edit” menu.
However, there isn’t a fast, one-click way to delete all your duplicate tracks from iTunes, but for good reason: not all songs that iTunes recognizes as ‘duplicates’ really are. Consider, for example, a “Live” version of a song and its studio version. Since the titles and track lengths are similar, iTunes often records these as duplicates, but to many users, they’re both worth keeping.
We’d recommend using iTunes’ duplicate-finding feature as a start, but taking the time to sift throught its results to delete only those duplicates you actually want to.