A musical episode combining the casts of The CW's "The Flash" and "Supergirl" has been promised since last summer, and Warner Bros. Television has announced the first official details -- including when fans can expect it.
The musical episode is titled "Duet," and will take place on the March 21 edition of "The Flash," with a lead-in on the March 20 episode of "Supergirl," similar to how last fall's four-show crossover between The CW's DC Comics-based shows kicked off with a short lead-in scene on "Supergirl." This falls roughly a year after the first TV meeting between "The Flash" and "Supergirl," which happened on the "Worlds Finest" episode of "Supergirl" in March 2016.
"Duet" will be directed by Arrowverse veteran Dermott Downs, who has helmed multiple episodes of "The Flash," "Supergirl," "Arrow" and "Legends of Tomorrow." The episode will include musical numbers from "The Flash" stars Grant Gustin, Jesse L. Martin and Carlos Valdes; "Supergirl" stars Melissa Benoist and Jeremy Jordan; and "Legends of Tomorrow" co-star Victor Garber and "Arrow" regular John Barrowman, showing that the episode will also include Arrowverse vets known for their singing chops, even if they aren't part of the "Supergirl" and "Flash" casts. "Supergirl" actors David Harewood and Chris Wood will also appear on "Duet," in "non-singing guest star appearances."
Earlier this month, "The Flash" and "Supergirl" executive producer Greg Berlanti confirmed that song-based villain the Music Meister will be the antagonist of the episode.
Much of the "Supergirl" and "The Flash" casts have prior musical experience, making such an episode a natural fit -- titular stars Melissa Benoist and Grant Gustin both performed on "Glee," Jesse L. Martin originated the role of Tom Collins on Broadway in "Rent" among many theater roles, Carlos Valdes played Andrej in the Broadway cast of "Once," and Jeremy Jordan has performed on Broadway and co-starred in the film version of "The Last 5 Years."
Keep reading CBR for the latest on the musical team-up between "The Flash" and "Supergirl,"