It’s really fun to see circular fandom between actors and showrunners.
Jesse L Martin is self producing a short film, and fundraising on Kickstarter. Joss Whedon apparently pledged “an outstanding amount” to the project. To thank him, Martin grabbed Flash co-stars Rick Cosnett and Carlos Valdes for a little a capella rendition of the Firefly theme. Take a listen.
We also know that Grant Gustin who plays Barry Allen on the show can carry a tune, so maybe a musical episode might be in our future?