Why Does I Tunes So Bad At Removing Duplicates?

If these are purchased items, and one of the tracks of each pair has a cloud download symbol, then try signing out of the iTunes store and back in again to resolve.

iTunes may create duplicates if the same content is repeatedly added from outside the media folder when it is set to make copies of anything that is added to the library, or is added from an external drive that hosts the media folder that was offline when iTunes was launched.

Apple's official advice on duplicates is here: Find and remove duplicate items in your iTunes library. It is a manual process and the article fails to explain some of the potential pitfalls such as lost ratings and playlist membership, or that sometimes the same file can be represented by multiple entries in the library and that deleting one and trashing the file will break any others.

Start in the Songs view. Use File > Library > Show Duplicate Items and then click Same Album to display exact duplicates as this is normally a more useful selection. You need to manually select all but one of each group to remove. Sorting the list by Date Added may make it easier to select the appropriate tracks, however this works best when performed immediately after the dupes have been created. If you have multiple entries in iTunes connected to the same file on the hard drive then don't send to the trash.

tt2