Umpass-stay was a male Klatooinian who worked as a drummer and bodyguard for the Max Rebo Band at the palace of the crime lord Jabba the Hutt on the planet Tatooine. Four years after the Battle of Yavin, he and the rest of the band performed the song Jedi Rocks for Jabba, who demanded they repeat the song but then dropped the slave Oola into his rancor pit when she refused his advances during the performance. The band stopped playing as the rancor devored the slave was by the rancor, and then witnessed the arrival of Princess Leia Organa disguised as the bounty hunter Boushh with the Wookiee Chewbacca as a prisoner.