Sorry, we have not watched this yet.
Decked out in caveman attire, Denver and the kids form a rock group (B.C. Rock) to compete in the city wide talent contest. Freddy Facknitts also form a group called Roborock (rock'n'roll robots). But Morton Fizzback and Dr. Funt steal the robot band right before the contest and the kids must go after them.
Sorry, we have not watched this yet.