Listen to Back in Gimmelshtump online. Back in Gimmelshtump is an English language song and is sung by Dr. Doofenshmirtz. Back in Gimmelshtump, from the album Phineas and Ferb: Across the 1st and 2nd Dimensions, was released in the year 2011. The duration of the song is 1:14. Download English songs online from JioSaavn.