Kids love music. We do a lot of singing and dancing, clapping and just generally making a lot of sounds.
A favourite thing to do though? Play musical instruments.
We're lucky enough to have a keyboard that I can pull Max right up to in his high chair. And he'll play for up to 20 mins (with the volume down low :). If you don't have that though - pots and pans work, or pill bottles with the lids securely attached can be the best shakers. Or buy a kazoo for 50 cents... Put on some music and go to town. We like Raffi best of all, and his album Singable Songs for the Very Young.