The Flash and Supergirl, both starring Glee alums and accomplished singers Grant Gustin and Melissa Benoist, will crossover for a special two-part musical episode this season, in addition to the four-part crossover hitting all for DC shows on The CW.

The announcement came at the TCA presentation for The CW Thursday, opening up their DC TV shows panel with a bang. The crossover will include one episode of each series. While they plan to use "pre-existing songs" for the bulk of the musical numbers, they're exploring writing one original song for each episode, giving The Flash and Supergirl each their own brand-new song.

A musical episode for each of the two shows has been an oft-asked question, since both leads have sung - and even on TV - in the past. While karaoke teased the idea on The Flash, most producers and stars, when asked, have simply said things like "that would be fun." Now, it's happening, and it's happening this season as part of a two-episode crossover.

"So many times, it's a musical episode off the set," EP Greg Berlanti said. "On all of the shows we like to use all of the actors' talents." He teased that there will "probably be an element of the songs being in the characters' heads," rather than them being a main plot point. While nothing is confirmed, Berlanti does hope to bring in some actors from Arrowand Legends of Tomorrow for a musical number or two, as well. Victor Garber, John Barrowman, and more actors have singing backgrounds, after all.

We will keep hope alive that Music Meister, voiced by Neil Patrick Harris on Batman: The Brave and the Bold in a musical episode, will be the reason why they're suddenly singing.

Supergirl and The Flash debut on Monday and Tuesday night at 8pm the first week of October, 2016.