Granted, we don’t yet know what first brings the Supergirl crew over to Earth-1, or perhaps what universe the Music Meister hails from.
The two-part event will feature Glee alum Darren Criss as the Music Meister, whose menace is said to begin in the March 20 Supergirl episode, and continue in the following night’s Flash.
You can get a good sense of the whole cast’s musical prowess here, but stay tuned for more on Flash and Supergirl’s musical team-up.
The character’s presence has only been referenced as one of the headlines from Barry’s future vision, in which he’d apparently secured a six-figure book deal.