iPad Air 2 (iOS 9 beta 5, happened in beta 3 and 4 too), iMac running El Cap (PB4, happened in PB3 too) I've never seen this problem before but now have it every time I sync. I have a lot of music and playlists. Here is an example of part of my playlist library before syncing: 1980s (2000 songs) 1990s (2000 songs) 2000s (2000 songs) 2010s (2000 songs) for example. If I add one new song to my iTunes library on my iMac in each playlist, after syncing to my iPad Air 2, I now have: 1980s (2001 songs) 1980s 1 (2000 songs) 1990s (2001 songs) 1990s 1 (2000 songs) 2000s (2001 songs) 2000s 1(2000 songs) 2010s (2001 songs) 2010s 1 (2000 songs) Same on my iPad in the music library AND in apps that can access that library, such as DJay2. When I next sync back to my iMac's iTunes library, the Mac has the same amount of playlists as the iPad. If I now add one more song to each playlist and resync, I then have the following situation on the iPad: 1980s (2002 songs) 1980s 1 (2000 songs) 1980s 2 (2001 songs) 1990s (2002 songs) 1990s 1 (2000 songs) 1990s 2 (2001 songs) 2000s (2002 songs) 2000s 1 (2000 songs) 2000s 2 (2001 songs) 2010s (2002 songs) 2010s 1 (2000 songs) 2010s 2 (2001 songs) This is ridiculous. Anyone else having the same issues? Is there a workaround or quick fix? Is this even an iOS9 bug or a standard bug that can happen with any iOS-OSX combo? I have not yet removed music to resync as I have quite a lot of it and it will take a long time to resync back to the iPad Air 2.