‘The Flash,’ ‘Supergirl’ Musical Crossover Spoilers: Neil Patrick Harris Cast As Music Meister?

“The Flash” and “Supergirl” executive producer Greg Berlanti announced that Barry (Grant Gustin) and Kara (Melissa Benoist) will be battling the Music Meister in the upcoming musical crossover event between the two CW series later this season.

“It is going to be the Music Meister,” Entertainment Weekly quoted Berlanti as saying at the Television Critics Association’s (TCA) press tour on Sunday, Jan. 8. when asked about the villain in the much anticipated crossover. “We’re finishing writing the script this weekend.”

Music Meister was created by Michael Jelenic and James Tucker for the animated series “Batman: The Brave and the Bold’s” own musical episode, “Mayhem of the Music Meister!” In the episode, Music Meister — who has the power to control people through song —falls for Black Canary until she rejects him due to her feelings for Batman.

Music Meister was voiced by Neil Patrick Harris on the Cartoon Network series, but could the actor play the live-action version of the character in the “The Flash”— “Supergirl” musical crossover?

“We haven’t gone about casting it yet,” Berlanti revealed. “But it’s the right question, though.”

“We’re certainly huge fans of him and as the casting process proceeds we’ll see what happens,” Berlanti’s fellow executive producer Andrew Kreisberg told reporters at TCA, according to IGN.

Harris told IGN last month that he’s aware that some fans would like him to play the Music Meister in the crossover, but at the time, it seemed that he hasn’t heard anything about it yet from Warner Bros. TV.

“I did the Music Meister in a recording booth in L.A. 15 years ago or something. It was a fun episode. It’s always fun to sing so I don’t know. We’ll see,” said Harris when asked if he would play the character in the crossover.

While fans have to wait a little longer to find out whether Harris will be singing as the Music Meister in the crossover, Kreisberg confirmed that “there’s going to be people from both shows singing” and clarified that the special event is “going to start on ‘Supergirl’ and … going to be resolved on ‘Flash.’”

Kreisberg added that the events in the crossover will propel ongoing storylines on both shows. “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,” he said.

When asked whether the crossover would feature covers or original songs or combination of both, Kreisberg said: “We’re still writing the script and trying to figure out exactly what we’re going to do.”

“The Flash” and “Supergirl” are currently on hiatus. “Supergirl” returns to the CW with an all-new episode on Monday, Jan. 23 at 8 p.m. EST, while “The Flash” comes back on Tuesday, Jan. 24 on the same timeslot.