In the nineteenth century, E. T. A. Hoffmann invoked the Magic Flute as an example of restraint in orchestration: despite the opera’s trials and tribulations, the music never descends into bombast. Other critics were underwhelmed by the orchestration, which seems devoid of the instrumental effects promised by the title. This essay argues that the magic of Mozart’s orchestration lies in the ways in which it constructs different relationships with the stage action. Whether it’s the acoustic portraits of characters such as the Three Spirits, the pragmatics (and illusions) of on-stage musical performance, or the musical control of performing bodies by seemingly self-playing instruments, Mozart’s orchestration thematizes relationships between sounds and their sources. This essay puts the instruments of the pit in dialogue with the instruments on stage and, in so doing, illuminates the subtle ways in which Mozart uses the orchestra, as much as his characters, to tell his last story.