The Flash Supergirl Musical Crossover: 14 Easter Eggs & References In 'Duet' You Need To See

13. The Broadway Stars

The Flash has a big advantage over most other TV shows when it comes to doing a musical episode, because unlike, say, Buffy, its cast are very talented and proven musical performers, and this extends well-beyond the lead duo.

Indeed, they have the luxury of using the narrative device to pick-and-choose which supporting characters get prominent roles in the episode, meaning they can unleash the talents of some, while the likes of Candice Patton and Danielle Panabaker don't have to sing.

Jeremy Jordan (Winn) is a well-known Broadway performer, having appeared in the likes of Newsies, Rock of Ages, and perhaps most pertinently for this episode, West Side Story. He also had a main role on the short-lived musical drama Smash. Carlos Valdes, meanwhile, has a musical career under the name Tha Los, where he's released a couple of EPs, and appeared in Tony-nominated musical Once.

John Barrowman has a long history of singing and dancing, appearing in a number of stage musicals and releasing numerous albums as well; Jesse L. Martin showed off his crooning chops last year over on Earth-2, and previously starred in the musical Rent; and Victor Garber has spent a lot of his career on (and off-) Broadway, including picking up a Tony nomination for the musical Damn Yankees.