iTunes doesn't sync any music to my Nano

I have a 2nd gen Nano and the latest iTunes update as of July 6 2015. Rainbow icon (v 12.2.0.145). Running Windows 7.

I had trouble with iTunes losing my music library after an update several months ago. Finally I copied my iPod music to my computer and then into iTunes. It's all there and plays, but won't sync anything to my iPod. I ended up restoring the Nano. Still nothing. Then today I bought an album. It won't put that on my iPod either. It's says it is syncing, but the only thing I have showing on there is the little yellow bar.