If the sync to your ipad doesn’t complete properly then the ipod music app can come up and then disappear.
Very distressing. Google search shows two simple fixes. Add or delete a song on iTunes and resync. This resets the music database. See http://www.ipadforums.net/ipad-help/5770-ipads-music-app-crashes.html
But simplest is to start the video app. This resets the sync information enough for the music app to run.
Worked for me!