HT201812 I have thousands of duplicates. "Show Duplicates" does half the work. Help.

I recently consolidated a couple incomplete backups into a brand new iTunes library on my Macbook Air.
Despite needing to load both collections to cover all my music, there are thousands of duplicate song files in iTunes.
I can use "Show Duplicates" to show all of them in one screen. But Apple's advice was to simply "select the duplicates I want to delete."
Now, I suppose I can take an extra day off work, Press Command and start to click on every other file listed for several hours and hope I don't mess up at any point and have to start over.
But I have to believe in this technologically advanced world, that there is a better way to accomplish this goal.
Please help me dear sweet Internet.


The first thing you should try to fix this problem is to sync your iPhone with iTunes over USB instead of WiFi. If that doesn't work. Delete the music that is corrupted on your iPhone from your iTunes library. Re-sync your iPhone with iTunes make sure it deletes the music. Then, reload the music on, and sync via USB. If none of that works, the only possible solution is to restore your iPhone's firmware.