The seven principal characters in the film are named after the notes of the musical scale - Do, Re, Mi, Fa, Sol, La, and Si. The credits list them only with these names, and after that, in the opening scene, the Master of Ceremonies presents the characters as puppets and explains who is who. In the closing scene, the Master of Ceremonies again shows the puppets and says that they may represent the simplest musical scale, but, using those seven notes, one could create a most complex musical composition.