Jonas Brothers

Jonas Brothers are a band consisting of three real-life brothers: Kevin, Joe and Nick Jonas. They appeared in the episode of Hannah Montana, titled Me and Mr. Jonas and Mr. Jonas and Mr. Jonas.
In the episode, they featured on a song with Hannah Montana called We Got The Party. 
They later joined Miley on the Best Of Both Worlds Tour as special guests, where they first performed their collaboration, and afterwards their own songs "When You Look Me in the Eyes" and "Year 3000", while Cyrus was changing from Hannah to Miley.
Jonas Brothers