The Aquabats

The Aquabats are a rock band consisting of superheroes.

Origin
They were once natives of the island of Aquabania, but their land was invaded by Space Monster M. The members of the Aquabats fled and vowed to defeat Space Monster M and free their land. They eventually came ashore on the United States, where they met Professor Monty Corndog, who gave them superpowers and instruments. Since then, they've protected the world from Space Monster M and many other villains. They even encountered GWAR at one point.