The upcoming musical crossover between "Supergirl" and "The Flash" isn't just going to be a fun gimmick. According to executive producer Andrew Kreisberg, the two-part story will have lasting ramifications on both shows.

“What I always loved about what Joss Whedon would do with ['Buffy’'s] ‘Hush’ or ‘The Body’ is he’d have these very special episodes, but they were intrinsic to the ongoing storytelling," Kreisberg told TVLine. "So when we get to the musical episodes, both Barry and Kara will find themselves at pivotal crossroads on their respective series, and the experience of going through the musical will have a great impact on both series moving forward.”

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No date has been announced for “The Flash”/”Supergirl” crossover, starring Grant Gustin and Melissa Benoist, both veterans of Fox’s musical comedy-drama “Glee.” Nevertheless, a few details about the upcoming mini-event were revealed during The CW’s presentation at the Television Critics Association winter press tour, which took place last weekend. For instance, executive producer Greg Berlanti confirmed the villain will indeed be the Music Meister, who can control people through song. What's more, the musical crossover will feature original songs and could include characters from any Earth or timeline in the "Arrow"-verse.

In addition to Gustin and Benoist, the two DCTV shows host a surprising number of musically-talented actors, including "RENT" alum Jesse L. Martin, "Godspell" star Victor Garber, "Finding Neverland's" Jeremy Jordan and John Barrowman, whose stage credits include "Beauty and the Beast," "Evita" and "Aladdin." Even though some of these musically inclined actors appear on shows like "Arrow" and "DC's Legends of Tomorrow," Berlanti already confirmed that there's a possibility for their characters to turn up in this mini-crossover.

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Starring Grant Gustin as the Scarlet Speedster, "The Flash" airs Tuesdays at 8 pm ET/PT on The CW. The series also stars Jesse L. Martin, Tom Cavanagh, Carlos Valdes, Candice Patton, Danielle Panabaker, Keiynan Lonsdale and more.

Starring Melissa Benoist as the Girl of Steel, "Supergirl" airs Mondays at 8 pm ET/PT on The CW. The series also stars David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen, Chyler Leigh as Alex Danvers and Jeremy Jordan as Winn Schott and features appearances by Calista Flockhart's Cat Grant as well as Tyler Hoechlin's Superman.