Playlists and songs will not sync to new iPad Mini 3

I have a new iPad Mini 3 (128 gb of memory, and iOS 8.4.1), and am trying to set it up as a new iPad. iTunes is 12.2.2.25, 64 bit, on a Lenovo laptop with 64-bit Windows 7.

When I try to sync from iTunes on the laptop to the iPad, not all playlists sync (do not appear on the iPad), and in some playlists, several of the songs do not sync. Some do, many don't. There does not seem to be any discernible pattern; perhaps half of my playlists sync, and the rest do not. (Apps and movies sync successfully; only music does not.) I am syncing with a USB cable. Most of my music is from my CD collection, but I do have a few albums and individual songs downloaded from the iTunes Store.

There is plenty of free memory on the iPad.

I have tried first checking sync all music in iTunes, then I tried checking individual playlists to sync. The results are the same in both cases -- not all playlists are transferred to the iPad, and in some playlists, not all songs transfer.

I have had iPhones since the 3G, and have had each generation of iPad and iPad Mini, and have never experienced this problem before, when setting up a new iOS device.