It will be a gleeful reunion on the Supergirl/Flash musical crossover, as Darren Criss has been cast as the episode’s villain, Music Meister.

Criss joins fellow Glee alums Melissa Benoist (Kara Zor-El/Supergirl) and Grant Gustin (Barry Allen/The Flash) in the musical event. Humorously, on Glee Gustin played Sebastian Smythe, a member of a rival show choir who was romantically interested in Criss’s Blaine Anderson. Benoist, meanwhile, played one of Criss’s show choir teammates, Marley Rose.

“With our Flash and our Supergirl being Glee alums, how could we not have them go up against another Glee favorite like Darren Criss?” says executive producer Andrew Kreisberg.

“We have been blown away by his talent over the years and we can’t wait to see what he brings to the Music Meister.”

Besides starring for five seasons on Glee, Criss is also a singer/songwriter and has starred on Broadway in How to Succeed in Business without Really Trying and Hedwig and the Angry Inch.

Criss tweeted his excitement at the casting news:

Music Meister debuted in an episode of Batman: The Brave and the Bold and was voiced by Neil Patrick Harris. Bullied as a child, Music Meister learned he could use his voice to hypnotize people to do his bidding. While hypnotized, Music Meister’s victims also sing and dance.

Despite appearing in this one episode, Music Meister has become quite a popular villain, so it should come as no surprise the crossover would use him.

Titled “Duet,” the two-night event will begin on the March 20 episode of Supergirl and continue on the March 21 episode of The Flash.

It will feature the musical talents of not only Criss, Benoist and Gustin, but also Jeremy Jordan (Winn Schott), Victor Garber (Martin Stein), John Barrowman (Malcolm Merlyn), Carlos Valdes (Cisco Ramon) and Jesse L. Martin (Joe West).

David Harewood (J’onn J’onzz) and Chris Wood (Mon-El) will appear in non-singing roles.

Garber and Martin have already had the opportunity to sing on Legends of Tomorrow and The Flash respectively, but it will be a lot of fun to see the remaining cast let loose as well.

Are you excited to see Darren Criss on the ‘Supergirl’/’Flash’ musical crossover?