The CW has an incredible track record with its crossover episodes - this past November's four show crossover between Supergirl, The Flash, Arrow, and DC's Legends of Tomorrow being a particular standout.
For Tuesday's episode of the Flash, the creators are combining some of the wildness of The Flash's comic book origins, with the strong singing skill set of its stars, to create a truly unique experience.
Here's a taste of "Superfriends", a song written by Crazy Ex-Girlfriend's Rachel Bloom:
And here's Melissa Benoist talking about her love of musicals:
Official show description:
TUESDAY, MARCH 21
“Duet” — (7:00:00-8:01:00 p.m. CST)
DARREN CRISS (“GLEE”) GUEST STARS AS THE MUSIC MEISTER IN THE FLASH AND SUPERGIRL MUSICAL CROSSOVER – Barry (Grant Gustin) and team are surprised when Mon-El (guest star Chris Wood) and Hank Henshaw (guest star David Harewood) arrive on their Earth carrying a comatose Supergirl (guest star Melissa Benoist) who was whammied by the Music Meister (guest star Darren Criss). Unable to wake her up, they turn to Team Flash to save her. However, the Music Meister surprises The Flash and puts him in a similar coma, one that Team Flash can’t cure. Kara and Barry wake up without their powers in an alternate reality where life is like a musical and the only way to escape is by following the script, complete with singing and dancing, to the end. Dermott Downs directed the episode with story by Greg Berlanti & Andrew Kreisberg and teleplay by Aaron Helbing & Todd Helbing (#317). Original airdate 3/21/2017.