Can I mass delete iTunes files?
every one of my files in iTunes has been duplicated twice. Is there a way to mass delete the two unwanted copies ?
iPhone 4S, iOS 7.0.4
Yes. The question is how to do it most efficiently.
Did this duplication happen all at the same time? In this case, it should be possible to cluster the duplicate tracks by sorting your library by Date Added. I'd use the Songs display for this, set to View As > Songs, and click on the Date Added column header. (Customize the column display if you need to, by right-clicking or 2-finger tapping or Control-clicking on the header row, and choosing Date Added from the pop-up menu.) Select the first duplicate track, scroll down, and select the last track while holding down the Shift key. Now hit Delete.
If the duplication did not happen all at once, some variation of this trick might be necessary, or we may need to go for a totally different approach — so post again in that case.
Happy hunting!