A Phintastic Ferbulous Musical!

Phineas and Ferb decide to make a musical.

Songs
What We're Gonna Do by Phineas

Trivia
Rollercoaster the Musical: This is the second musical in the series.

Take Two with Phineas and Ferb: The song Phineas sings contains the line "I know what we're gonna do" from the Take Two theme; which actually was taken from his catchphrase anyway.

Rollercoaster the Musical: The first song is based on Phineas's catchphrase.