Here's what I had to do, no thanks to the others on here who go at it like Apple, delete and restore.
No, you don't have to delete and restore. Just open a folder on your computer, call it something like iPad music, keep it open, open iTunes, select all your music, copy and paste it in the folder you just created, delete all your music from iTunes (relax, you just copied it into that folder). Select all the music in that folder, drop it back onto your playlist. Now, I renamed my playlist, because it was called untitled, originally, so if that doesn't work, rename, or delete and recreate your playlist, copy the music back over, sync, and they will play.
Worked for me, anyhow. Good luck!
<Edited by Host>