You are saying that is is seeing your library but you can't play music. Do you see the songs, albums and so on in the library? Did you try closing the Music App completely and launch it again?
Tap the home button once. Then tap the home button twice and the recents tray will appear at the bottom of the screen. Tap and hold down on any app icon until it begins to wiggle. Tap the minus ➖ sign in the upper left corner of the app that you want to close. Tap the home button twice. Launch the Music app again.
Sometimes it helps if you reboot the iPad when mysterious problems arise.
Reboot the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider if it appears on the screen - let go of the buttons. Let the iPad start up.