The CW has had a tremendous amount of success with their DC Comics-based TV shows in recent years. That has been especially true when they have a crossover event of some kind. The next one of these crossover events will be happening later this month when Supergirl and The Flash once again cross paths. The difference? This time it is going to be a musical. The upcoming musical crossover, titled Duet, has now been given an official synopsis.

The synopsis for The Flash and Supergirl musical crossover was reported by Den of Geek and it sounds a little whacky, but fun. Lighthearted fun mixed with action-packed sequences is a formula that has worked for the Arrowverse thus far, so it makes sense. Plus, this is a musical, so it probably shouldn't take itself too seriously. Here is the official synopsis for "Duet."

"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."

The Duet event is going to be loaded down with guest stars and is also going to be loaded down with tunes. It was revealed a while back that most of the music in the crossover event will be cover songs, but Greg Berlanti and the folks at The CW did bring in some big name talent to write a couple of original songs for the event. The Golden Globe-winning La La Land duo of Benj Pasek and Justin Paul have written a song entitled "Runnin' Home To You", which will be sung by Grant Gustin's Barry Allen. Rachel Bloom, who is the creator and star of The CW's musical comedy series Crazy Ex-Girlfriend has also written a song called "Super Friend", which Melissa Benoist's Supergirl will sing with The Flash.

Melissa Benoist used to star on Glee so we already know she can sing just fine, and as history would have it, Grant Gustin also co-starred on that Fox drama, so he should fare quite well when singing a tune written by some award winning songwriters. "Duet" is directed by Dermott Downs and was written by Aaron Helbing and Todd Helbing. The crossover event will start on Monday, March 20th with Supergirl before concluding in the Tuesday, March 21st episode of The Flash.