The upcoming musical crossover between Supergirl and The Flash has found its villain in The Music Meister. Created for the animated series Batman: The Brave and the Bold, The Music Meister was voiced by Neil Patrick Harris. The villains evil powers cause everyone to break into song.
Executive producer Andrew Kreisberg noted that the musical will be crucial to both characters' storylines.
"When we get to the musical episode, both Barry and Kara will find themselves at pivotal crossroads on their respective series, and the experience of going through the musical will have a great impact on both series going forward."
Harris isn't set to reprise his role in the live action version yet, but he isn't being ruled out by producers. The crossover will start on Supergirl and end on The Flash.