We developed an interactive music system called the Melody Slot Machine that provides the experience of manipulating a music performance. The melodies used in the system are divided into multiple segments, and each segment has multiple variations of melody. By turning the dials manually, users can freely switch between melody variations. When users pull the slot lever, the melody of all segments rotates, and a melody segment is randomly selected. Since the performer is displayed in the form of a hologram that moves in accordance with the selected variation of melody, users can enjoy the feeling of manipulating the performance.