This spring, "The Flash" and "Supergirl" will join forces for a two-episode musical crossover on The CW. Variety reports that this mini-event will be separate from the four-show crossover between "Arrow," "DC's Legends of Tomrrow," "The Flash" and "Supergirl," which is slated for November.

At the TCA press tour, executive producer Greg Berlanti confirmed the musical crossover and revealed that it will feature "mostly pre-exisiting" songs. However, he hopes to include at least one original song in each of the two episodes. Though no official date was announced, the crossover will air during the back-half of the season.

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"We've got such talented actors, 15 years from now when the last of these shows is going off the air, that would be a big regret [if we didn't do it] - it's too much fun not to," executive producer Sarah Schechter explained.

"The Flash" star Grant Gustin and "Supergirl's" Melissa Benoist are both alums of "Glee," where they covered popular songs. Between the four shows, DCTV hosts a surprising number of musically-talented actors, including Jesse L. Martin, Victor Garber, Jeremy Jordan and John Barrowman, among others.

Starring Grant Gustin, Jesse L. Martin, Carlos Valdes and more, "The Flash" returns to The CW on October 4 at 8 pm EST. The second season of "Supergirl" is scheduled to premiere on Monday, October 10 at 8 pm EST on The CW, switching networks after a first season on CBS.