Things are going to get musical on The Flash and Supergirl. In a crossover event on The CW shows, Barry Allen and Kara Danvers will face Music Meister, a villain from the animated series Batman: The Brave and the Bold.

Executive producer Greg Berlanti announced that Music Meister will appear in the crossover during the Television Critics Association winter press tour. He’s the perfect character for a musical episode since he can control people through song.

Casting, however, was not revealed. Neal Patrick Harris voiced the character on the animated show, but at present he isn’t locked in for the role. “We haven’t gone about casting yet. It’s the right question though,” Berlanti said during an interview with IGN.com.

“I’ve heard about it, but that’s as much as it has been. I mean, I did the Music Meister in a recording booth in L.A. … 15 years ago or something, you know, and it comes out a year later. It was a fun episode, it was a good thing to day,” Harris said. “But I’ve heard that Joss [Whedon] is involved in some way, but I don’t know if that’s true or not. … He wears a big zoot suit, from what I remember. The song was fun to sing, so I don’t know; we’ll see.”

Harris starred on Broadway in Hedwig and the Angry Inch and in Whedon’s musical webseries Dr. Horrible’s Sing-Along Blog. On Batman: The Brave and the Bold’s episode “Mayhem of the Music Meister” he voiced the character and controlled Batman, Green Arrow, Black Canary, and Aquaman.

The Flash and Supergirl are the best suited for a Music Meister appearance on The CW’s Arrowverse shows. Grant Gustin and Melissa Benoist were both on the FOX musical dramedy, Glee. Harris guest starred on that show, as did Black Jenner, who played Cat Grant’s son Adam Foster on Supergirl last year. Jesse L. Martin, who plays Joe West on The Flash, starred in the musical Rent on stage and film.

A date for the musical crossover episode has not been announced.