The following information is from the Adventure Timecomic book series. It may not be part of the same canon or continuity as the animated series.
Adventure Time: Marceline and The Scream Queens Issue 1 is an Adventure Time comic miniseries released in July, 2012. It was published by BOOM! Studios. It was drawn and written by Meredith Gran. The first issue has a backup story done by Jen Wang and the variant covers was drawn by Chynna Clugston, Lucy Knisley, Ming Doyle and Colleen Coover.
Thanks to a newfound interest in music, Princess Bubblegum joins Marceline's paranormal rock band for a tour across the Land of Ooo! But when they’re threatened by everything from scenesters to beasts born of self-doubt, can they make it to the RADDEST GIG EVER in time?!