The apartment residents have a band called the Talking Airheads, which features Shane on guitar; David on drums and a cowbell; the Schmuzzies on the marimba; Fido the Fly on trumpet; and Puppet as the songwriter. The band faces a setback when David's cowbell, attached to an imaginary cow named Clarabelle, disappears. David and Shane try to find the cowbell in the Great Big Bell Room, where Mrs. Foil has a giant bell but no cowbells. They fish for the cowbell in a boat out at sea, where they help Mrs. Foil go "tuba diving" with her tuba, and go for a ride in the Bicycle Room. All the while, Puppet tries to bring Clarabelle to the apartment by playing farm songs, which inspires David and Shane to look for her at Mrs. Foil's farm. They find Clarabelle and bring her back for their big musical performance.