Are you restoring your iOS 6 backup either from iTunes or iCloud? As I wrote earlier in this thread, the only thing that stabilized my Touch for music was NOT to restore my iOS 6 backup. It's been good since I bit the bullet and started over from scratch, but as it turned out, it wasn't entirely from scratch. I wrote a little bit more about the process:
After upgrading to iOS 7 and several hours of use, music started to go missing. I restored iOS 7 in iTunes and resync'd 50 GB of music (size on device after being transcoded on-the-fly to 128 Kbps AAC), and even though the iTunes progress indicator ticked off all 12,000 songs, it got stuck on "Waiting for changes to be applied", and after 8+ hours, it never finished. So, I unplugged the Touch, and I found it only had about 4,000 songs on it. When I plugged it back into iTunes, iTunes reported over 30 GB of "Other", which I guess represents the orphaned corrupt songs. I went through several rounds of this, and the only thing that helped was to not restore my iCloud backup. Fortunately, I didn't lose all my settings. The Safari bookmarks and iBooks current page info were preserved thanks to iCloud (separate from "backups", which again I did not restore), and my Tapatalk ID kept my subscribed forums intact. I use Converter+ and used that program's Email Template feature to email myself all my custom templates, which contain links to install the templates, so I didn't lose them. Of course, I had to re-enter all my passwords for Tapatalk and Safari.