By Natalie Abrams
March 21, 2017 at 12:00 PM EDT
The Flash/ Supergirl Crossover
Credit: CW

It’s time to play the music, it’s time to light the lights, it’s time to see singing superheroes on The Flash-Supergirl musical crossover tonight!

During Tuesday’s episode of The Flash, both the Scarlet Speedster (Grant Gustin) and Supergirl (Melissa Benoist) get trapped within a movie musical by new villain Music Meister (Darren Criss), leading to an hour of melodic high jinks in which Barry and Kara must sing and dance their way out of this alternate reality. How did this harmonious hour come to be? EW sat down with executive producer Andrew Kreisberg to get the scoop:

ENTERTAINMENT WEEKLY: Where did the idea first come from to do a musical crossover?
ANDREW KREISBERG: I think we’ve always been talking about doing it from the very beginning, more of in a joking way, just because we had Grant, and we had Jessie Martin and Carlos Valdes, and we worked with Victor Garber, and then John Barrowman joined. We had this plethora of theater talents, so it was always like, “Oh, we should definitely do that,” and we heard it from the fans, too. “When are you going to do a musical considering the cast you have?” Once we got Supegirl off the ground, then we had Melissa and Jeremy, it was like, “We kind of have to do this.” But Greg [Berlanti] was really the driving force this year about making it a reality. Once we decided we were going to do it, and Greg announced it at the TCAs, it was sort of like, “Well, we’re definitely doing it!”

What’s been the hardest part about putting together crossover?
The hard part really was picking the songs. I mean, it was like, “What songs were we going to use?” We went through a lot of songs, a lot of going through our own iTunes. Were we going to use modern songs, old songs, or The American Songbook? And so it became this treasure hunt every night. We’d come in, “What about this song?” Greg had always wanted Melissa to sing “Moon River,” and when we were trying for the big number, Greg just came in one morning and said, “It just popped in my head — ‘Put a Little Love in Your Heart,'” so that’s where that came from. We were approached by Rachel Bloom, who reached out to us, and she really wanted to write a song for us, and Greg had a relationship with Pasek and Paul, and we sat down with them. We hadn’t even seen La La Land with them, but Greg had been such huge fans of theirs.

Was there any one song you wanted to get in?
There wasn’t one song we definitely wanted to get in. Greg had always wanted Melissa to sing “Moon River,” so that was really important to him, and she sings so beautifully. “More I Cannot Wish You” actually came from Victor Garber. Victor had always wanted to sing that, so that’s where that came from, and having that song about a father singing to his daughter sort of helps influence the storyline that we came up with, with them being trapped in the movie musical.

Set up that world for the viewers.
Barry and Kara are both whammied by the Music Meister, played by Darren Criss, and they wake up trapped inside an alternate dimension, which is a movie musical come to life. So they’re caught up in the plot of this musical, which involves gangsters and gun malls and a West Side Story setup with rival gangs and their kids falling in love. It cherry picks little bits of other movies — there’s a little Guys and Dolls, there’s a little West Side Story, there’s a little Singin’ in the Rain, and it’s all amalgamated into the musical that our heroes find themselves in.

How do Kara and Barry take to this?
Obviously, at first they are both incredibly shocked, but part of the reason that they’re trapped in a movie musical is that they both loved musicals when they were kids. We get to see in this episode a flashback to Barry when he was a child and his mom, played by Michelle Harris, and how when he was feeling down, she would always show him musicals. For Kara, I think we said on Supergirl that Wizard of Oz was her favorite. How could it not be? It’s about a girl who gets shipped away by a tornado just like Kara was when she was a child. So we’ve always envisioned that when she was first here and sad, the family sat down and made her watch The Wizard of Oz and made her feel better.

What can you tease for some of the other characters? How different they are from what we know of them?
Yeah, we get to see everybody. There’s a little bit of Wizard of Oz where our characters are playing other characters in the movie musical, so it’s, “and you were there, and you were there, and you were there.” It’s definitely fun to see like Malcolm Merlyn and Cisco and Winn playing very different characters inside this musical.

You have a plethora of talent, but who has surprised you during this process?
I don’t want to say it’s a surprise, but it’s the speed with which Grant and Melissa learned their dancing. I realize they have a lot of fight choreography and they learn that stuff, but I think for them it’s like muscle memory, back to their Glee days of just having to learn very complicated dance moves on the fly. If they came in and did an elaborate fight sequence, I’d say, “Well, that’s just their jobs,” but to me, I look at people dancing, and all of it’s a mystery to me, so they were able to learn this elaborate dance for a two-minute long song, and they would just perform it every single time and never mess up. That I was truly in awe of.

The last time they crossed over, Barry and Kara were able to learn something from each other. What do you think they’ll learn from the crossover?
Well, they definitely learn that the other person is a good singer. [Laughs.] I think this time, when we come into this episode, both of our heroes are at odds with love. They’re both experiencing turmoil in their interpersonal relationships, so the purpose of the journey that they’re going on in this episode is to square the circle with love with respect to their respective lovers. It’s great because they’re best friends, and you don’t often see stories about best friends between men and women, and it’s really nice. They’re just there for each other, and it has such an easygoing energy. When you pair Barry with Oliver, it’s all about the distinctions and the differences, and with them, it’s all about how alike they are, so it’s really nice to just watch them be together and to go through a journey as friends.

How does the Music Meister compare to other villains we’ve seen on the show before?
He’s certainly in love with his own villainy a lot more than others. He’s got a zest for life. He comes in and just sweeps them all off their feet, and he’s a bit of a showman, so it’s a lot of fun. Darren so brings him to life. I’m not sure who we would have gotten to do it if Darren had said no, but it turned out to be one of those things where we wanted Darren, and Darren actually wanted the part. He’d heard about it. It was very kismet, and it’s so much fun to see them all reunited from Glee.

Darren mentioned the one thing he missed out on was getting to provide some songs.
I know. I know. By the time we closed him, we were already down the path. The songs had been recorded, but hopefully this one will be a big success, and he’ll come back, and then we can do another one.

Are you guys interested in doing another one?
If we survive this one and the fans like it, as always with any of these things, we gauge the fan reaction to it. If it turns out to be a, “Yeah, that was cute, but don’t ever do that again,” we won’t. But who knows? Every time we do one of these things, like go to Earth 2 or have a musical episode, some of that stuff we gauge by the fan reaction. Like King Shark, people were so excited about that one minute with him, we were like, “Well, we’ve got to bring him back now!” So we’ll see what people say.

The musical crossover will kick off at the end of Supergirl’s March 20 hour, with the majority of the action taking place during The Flash‘s March 21 episode; Supergirl airs Mondays at 8 p.m., and The Flash airs Tuesdays at 8 p.m. on The CW. Get behind-the-scenes scoop here, check out photos here, and read our interviews with Darren Criss here, Grant Gustin here, Melissa Benoist here, John Barrowman here, Jeremy Jordan here , and Carlos Valdes here.

Episode Recaps



Kara (Melissa Benoist) steps out from her super-cousin’s shadow to become Supergirl and defend National City in the third Arrowverse show.

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  • Andrew Kreisberg
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