The answer finally arrived when a crossover between The Flash and Supergirl was announced for the tail end of the latter’s freshman season.
So, when it was announced Supergirl would be joining The CW, network president Mark Pedowitz was quick to tease even more crossovers.
While the crossover episode, ‘Worlds Finest’, drew some criticism, it was largely well-received by fans of both Supergirl and The CW’s DC universe.
Additionally, since he has experience working with musicals both on Buffy and Doctor Horrible, he’s uniquely qualified for the job of directing a Flash and Supergirl musical crossover.