From a high school Glee Club to super heroes and villains, three former Glee cast faves Grant Gustin, Melissa Benoist, and Darren Criss reunite for a TV crossover.

The network has been crossing-over a lot lately with their super hero series and now they are taking it one step further with a two part musical Flash/Supergirl episode. Yes we said musical. Criss will be returning to the small screen to guest star with his former cast mates as the Music Meister villain.

With our Flash and our Supergirl being Glee alums, how could we not have them go up against another Glee favorite like Darren Criss? We have been blown away by his talent over the years and we can’t wait to see what he brings to the Music Meister.” – executive producer Andrew Kreisberg .

That won’t be the only voices you’ll here, joning Criss, Benoist and Gustin, will be Jeremy JordanVictor Garber, Carlos Valdes,  Jesse L. Martin and John Barrowman. Now that’s a line-up! The musical crossover event will sing-off with Supergirl Monday, March 20th and finish with Flash on Tuesday, March 21st.