Benson Fong, who appears as an extra during the opera scenes, later returned to the series to play Tommy Chan, Charlie's #3 Son.
Stage manager Maurice Cass vows that the opera will go on "even if Frankenstein walks in!" Audiences were well aware that this in-joke referred to star Boris Karloff, who was in the theater at the time.
The Mephistopheles costume from "Faust" worn in the film was originally made for Lawrence Tibbett to wear in Metropolitan (1935).