Can't play music on iPad

Is iTunes running on the computer hosting the music? Some other basic things to double-check... that your iPad is connected to the same network as your home sharing iTunes library and that you are signed into the correct Apple ID in Settings>Music.

If all that looks correct and it still isn't working, try turning home sharing off in Settings>Music, restarting your iPad (hold the power and home buttons until you see the Apple logo, then release), as well as your computer, then turn home sharing back on again.

Home sharing only stream music to your iPad over your wifi network. When you are out of range and not connected to your wifi network it cannot connect to your home sharing library, leaving you with only the music actually stored on the iPad.

In order to have access to your music outside of your home wifi network, you either have to sync the music to your iPad so it is stored locally, or subscribe to iTunes Match. With iTunes Match, your entire music library (up to 25,000 songs) is stored in iCloud and can be download and played anywhere you have a connection to the internet.