About two weeks after the 12.4 release, Apple comes with a new update for iTunes.
In iTunes 12.4.1 improvements are made for VoiceOver and a number of bugs of the previous version have been resolved.
This update does not come with interface changes and other changes visible to the user.
One of the most common errors on version 12.4 is solved in iTunes 12.4.1. Problem syncing photos from iPhone. "iTunes Can not sync photos to your Photos Library Because the iPhone is not yet available. Please try again later."
The update is available on all operating systems OS X, via App Store / Updates.