The Firefly is a 1937 American historical musical film directed by Robert Z. Leonard and starring Jeanette MacDonald, Allan Jones and Warren William. The film is an adaptation of the operetta of the same name by composer Rudolf Friml and librettist Otto A. Harbach that premiered on Broadway in 1912. The film used nearly all of the music from the operetta but jettisoned the plot in favor of a new storyline set in Spain during the time of the Emperor Napoleon I. It added a new song, "The Donkey Serenade" (a reworking by Herbert Stothart of Friml's 1918 orchestral piece 'Chanson'), which became extremely popular, as was one of the Friml songs, "Giannina Mia". The original release prints of the film were elaborately tinted with Sepia-Blue, Sepia-Orange and Sepia-Blue-Pink.