I'm proud to say I solved the horrible music problem, at least for now.
I bought Emma They Might Be Giants' kids' offering, No, on Friday, and she adores it. We haven't had anything else in her CD player since. If you haven't heard it, you should. It's not just for 3-year-olds. (It's billed as a family CD, but almost any song on it could be on an "adult" album. There is one that's a sort of weird choice for kids, and another mentions coffee and beer. We suspect those were leftovers used to round out the collection.) But it's hilarious to listen to her sing "No means no" and "I'm not your broom." We're all about Fibber Island and Robot Parade, too. Plus, it's plenty long for her to fall asleep before it's over (knock on wood), so she doesn't need to call us back at bedtime.
I'm not saying she's forgotten all about Tunes for Tots; I'm sure they'll be back in rotation at some point. But possibly not before a few can get lost ...