Prior to the premiere of Supergirl on CBS in the fall of 2015, fans speculated about whether Kara Danvers (Melissa Benoist) would ever crossover with The CW's slate of DC TV shows: Arrow, The Flash, and Legends of Tomorrow. However, little over a year ago, it was announced The Flash's Barry Allen (Grant Gustin) would, in fact, be traveling to National City for a crossover episode on Supergirl - with it later being confirmed that all four series exists within the multiverse. Then, after Supergirl moved to The CW for the show's second season, Kara traveled from her homeworld to Earth-1 for the 'Invasion!' crossover event.

However, the Girl of Steel is confirmed to partake in a second crossover event this season, Supergirl and The Flash's musical crossover that will air late in March. Batman: The Brave and the Bold's Music Meister will serve as the villain, played by fellow Glee alum Darren Criss. Now, after The Flash's episode of the musical crossover, 'Duet', filmed in Vancouver this past week, set photos offer fans their first look at Criss in costume as the musical villain.

Photos from the set reveal Criss won't don the zoot suit and fedora worn by Music Meister in Batman: The Brave and the Bold. Instead, Criss sports a more toned down black tailored suit, with certain red flourishes that may hint at the character's bigger personality - and superpowered vocal ability. In the photos, Criss is joined on set by Carlos Valdes (Cisco Ramon aka Vibe), Keiynan Lonsdale (Wally West aka Kid Flash) and David Harewood (J'onn J'onzz aka Martian Manhunter). Take a look:

#TheFlash filmed its musical crossover last night in a snowstorm w/ Darren Criss as Music Meister https://t.co/OjxR5FZ1Wh pic.twitter.com/WHUxHWKVJA— HollywoodNorth.buzz (@yvrshoots) February 4, 2017

#TheFlash shooting a scene with Kid Flash, Vibe, Martian Manhunter & Darren Criss as Music Meister (Homer and Dunsmuir) @WhatsFilming pic.twitter.com/0IAWEHM9x8— Carolina (@thereCgoes_) February 4, 2017

#TheFlash shot a scene with Kid Flash, Vibe, Martian Manhunter & Darren Criss as Music Meister in Dunsmuir and Homer today #yvrshoots pic.twitter.com/3HIJo1ExWX— Carolina (@thereCgoes_) February 4, 2017

It was previously reported that Criss, Gustin, Benoist, and Valdes will have singing roles in the musical crossover, in addition to The Flash's Jesse L. Martin (Joe West) as well as Legends of Tomorrow's John Barrowman (Malcolm Merlyn) and Victor Garber (Professor Martin Stein). The Supergirl and The Flash crossover will include at least two original songs, "Superfriends" written by Crazy Ex-Girlfriend creator/star Rachel Bloom that will be sung by Gustin and Benoist, as well as "Runnin' Home to You" by La La Land writers Benj Pasek and Justin Paul sung by Gustin. In addition to those mentioned, the musical crossover will include Chris Wood as Mon-El, though the actor won't have a singing role.

Specific details concerning the plot of the musical crossover, which is said to take place mainly in The Flash's 'Duet' with a short lead-in from the preceding Supergirl episode, have yet to be revealed. Based on these set photos, it seems likely Music Meister is attempting some kind of heist when approached by Kid Flash, Vibe, and Martian Manhunter, but it's unclear where in the episode this sequence takes place. Perhaps Supergirl and Flash have been incapacitated somehow, leaving their friends to confront Music Meister.

Still, no matter what Music Meister's evil plan is revealed to be, considering the musical talent assembled for the crossover - both in front of and behind the camera - The CW will be able to deliver a truly unique superhero experience. Of course, whether superheroes have any business breaking out into song on their shows has been debated among fans. But, based on non-spoiler tweets and Instagram photos posted from the set of The Flash and Supergirl's crossover, it seems the cast and creative team are excited about the musical event. Take a look:

I may be the only person who sits at the crossroads of loving superheroes & musicals but with so much talent in this I'm okay with that :)— Greg Berlanti (@GBerlanti) February 4, 2017

The last time I worked with this dude, HE was the bad guy singing at ME. Oh how the tables have turned , @grantgust . Talk about a #tbt @cwtheflash A photo posted by Darren Criss (@darrencriss) on

Iris West.#theflashseason3 #crossover A photo posted by David Harewood (@davidharewood) on

All play and no work. @christophrwood @grantgust @davidharewood #martianmanhunter #theflash #monEl A photo posted by David Harewood (@davidharewood) on

Next: Powerless Has Ideas For Grant Gustin Cameo

Supergirl continues Monday February 6 with ‘The Martian Chronicles’ at 8pm on The CW. The Flash continues Tuesday February 7 with ‘Untouchable’ at 8pm on The CW.

Source: Various [See Above]