Dd2's fave is the Wicked soundtrack. She is going to learn some songs on the piano and dd3 will sing - for their school family music night. They are so excited about it - cute.
As far as kid music:
Hello World by Red Grammer
Teaching Peace by Red Grammer
Still Growing by Tom Hunter
are all absolute MUST HAVES.

We listen to a variety of music on the radio. Other than the Wicked soundtrack and Vicci Martinez' From the Outside In, we don't usually have cds that go from the house to the car.