The chorus girls - among them Lucille Ball - chained to the wall in the "No More Love" number are actually nude. The number was filmed during the night, when no studio bosses were around on the lot, with a minimum of technicians involved.
According to' Lucille Ball''s autobiography, often the naked slave girls were left chained up high in the rotunda in between shots and retakes. One day while feeling ill, Lucille fainted, her fake chains gave way and she fell, almost hitting and getting burned by the lights. Another extra playing a slave driver caught her, and she was unharmed.
The studio had say over which girls Busby Berkeley could or could not use in his chorus lines and could reject one of them for any reason, though Berkeley usually fought for all of his casting decisions. For this film the studio rejected only two members of the chorus--Barbara Pepper and Lucille Ball.
Gloria Stuart was cast without taking a test. When Samuel Goldwyn was searching for an actress to play Princess Sylvia, Eddie Cantor suggested Stuart. Goldwyn took one look at the actress and decided that she was perfect for the role.