The CW has really made an event out of its annual superhero crossovers. Every year they get bigger and better.

Now with Supergirl officially part of the Arrowverse, it’s providing an opportunity to really get creative.

On the heels of last year’s four show Heroes vs Aliens event, The Flash and Supergirl will finally have their much talked about musical crossover. The CW recently released the synopsis for the episodes where Barry, Kara and their friends battle the Music Meister.

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.

Also performing songs will be Legends of Tomorrow’s Victor Garber and John Barrowman, Supergirl’s Jeremy Jordan and The Flash’s Jesse L. Martin and Carlos Valdes. The action takes place in the 40s with a mix of original and cover songs.

Like previous crossovers the action begins at the end of the Monday, March 20 episode of Supergirl titled Star-Crossed and picks up the following night on The Flash with Duet.

Supergirl airs Mondays at 8 pm and The Flash airs Tuesdays at 8 pm on The CW.

Source: Comic Book Resources