The CW is out with its first promo for the upcoming Flash/Supergirl musical crossover.

The 10-second teaser shows Grant Gustin and Melissa Benoist, elegantly dressed and dancing. In the episode titled “Duet,” the Music Meister sends Supergirl and the Flash to a world where life is a musical and the only way to escape is to sing and dance.

The story will first be set up at the end of the March 20 Supergirl episode and will then continue the following day on The Flash. Directed by Dermott Downs, it will include singing performances from Gustin, Benoist, Jesse L. Martin, Victor Garber, Carlos Valdes, Jeremy Jordan, and John Barrowman. There also will be non-singing guest star appearances from Supergirl’s David Harewood and Chris Wood.