How to Delete Duplicate Songs From an iTunes Library
Your iTunes library is your favorite place to store, manage and share your music. Unfortunately, occasionally you run out of space to keep all of your songs or you mistakenly have multiple copies of songs that you don't need. You can always free up room on your hard drive by deleting duplicate songs from your iTunes library.
Open your iTunes application. If you have a Mac, it's accessed through your dock. If you have a PC, it's accessed through the icon on your desktop or from the start menu.
Click "View" from the iTunes navigation bar and scroll down to "Show duplicates." This brings up a list of all the items in your iTunes library that share a title name and an artist.
To delete songs individually on a PC, right click on the particular song and scroll to "Delete" from the list of options. If you are using a Mac, right click by holding down Ctrl and clicking on the single mouse button, then choose "Move to Trash" from the list of options.
Confirm the deletion. Be sure to move it to the trash; otherwise the song name remains in the library but the file path is deleted, thereby creating a broken link.
Select multiple songs to be deleted (on a PC) by holding down the Ctrl key and clicking on the songs with your mouse. On a Mac, you can select multiple songs by holding down the (Apple or Command) key and then clicking with the mouse button. As in the above step, right click on the group of chosen songs and select "Delete" or "Move to Trash" from the list of options.
Switch out of the "Show Duplicates" view when you are done deleting your extra songs by going back to the top iTunes file menu and selecting "View > Show All." This returns you to your normal iTunes library view.