iMDeduper is software to find and delete duplicate songs on iTunes faster for Mac. You can customize which tag to be compared. After search, you can use auto marking to automatically mark duplicate songs for deletion.
What's new in this version:
Version 2.1.0 has been released : Add has artwork column, Able to sort (sorting is per group basis), Mark Selected, Unmark selected, Mark All and Unmark All in Edit menu, Bug fix