So long as Supergirl and The Flash were going to be flexing their pipes for a musical duet, The CW would naturally want to keep things in the family, right? Yes, the musical stylings of Crazy Ex-Girlfriend will be present in the crossover event, as Rachel Bloom contributes a ‘Super’ song.

BuzzFeed revealed that Crazy Ex creator and star Rachel Bloom wrote an original “Superfriends” tune for the March 21 episode, having lobbied The CW to contribute. The song will naturally be performed by Grant Gustin and Melissa Benoist, while Bloom explained of her involvement:

As soon as I heard that they were doing a musical crossover, I e-mailed Mark Pedowitz who connected me to Greg and Andrew. I immediately offered them my services. As soon as they picked one of my song ideas, I hopped on the phone with my old Robot Chicken boss Tom Root and we brainstormed and, based on that brainstorm, I wrote up the song ‘Superfriends.’ I am so excited to contribute more to the upward trend that is musicals in television and film. Music can be one of the most amazing and efficient forms of storytelling and character development. Also, it was really fun to write a comedy song for two superheroes.

The two-part event will feature Glee alum Darren Criss as the Music Meister, whose menace is said to begin in the March 20 Supergirl episode, and continue in the following night’s Flash. Also lending their voices will be Jesse L. Martin, Carlos Valdes and Jeremy Jordan, along with Legends of Tomorrow stars Victor Garber and John Barrowman. Supergirl cast David Harewood and Chris Wood will also appear in non-singing roles, while you can get a good sense of the whole cast’s musical prowess here.

We’ll likely hear of additional confirmations soon, but what else should Flash and Supergirl’s musical team-up bring?

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