Disney XD’s hit Star Vs. The Forces of Evil has a surprise up its sleeve in next Monday’s episode – rocker Patrick Stump (“Fall Out Boy”) appears vocally to play a character who comes to the aid with a brand new song.

On the episode “Face The Music”, which premiere’s Monday March 27th at 7pm EST – it’s Star’s Song Day. Star and Marco work with principled songstrel,’Ruberiot’, to create a ballad for the event. Stump guest stars as Ruberiot. Here’s an exclusive first look clip:

Stump has appeared on camera on several series (including House and Law & Order) but this is his first cartoon work. Asked about the differences between voice acting and singing, Stump said, “I like voiceover because it’s like being a singer. I like getting to use my voice as a different instrument, as something other than just a purely musical one. Even the singing as Ruberiot… I’m not singing as me, I’m singing in character in reaction to stuff. It’s a very different experience than just singing to perform a song. It’s really surprisingly natural, in terms of there is a microphone, there’s a studio, it’s really not very different from recording a pop record.”

“Ruberiot is an artist,” said Stump in a recent interview. “He takes what he does very seriously. He wants to write songs for the Princess and he’s really nervous about that. I think he’s a bit star struck by her.”