A hybrid musical instrument and a PDA form a musical performance system, and a user controls the hybrid musical instrument by means of the PDA; when the user pairs the hybrid musical instrument with the PDA, the musical instrument converts an identification code to a machine-recognizable image such as an image of a QR code on a monitor display, and the PDA takes in the image of QR code through an image pickup device; the PDA restores the image of QR code to the identification code, and stores it in a memory; and the identification code is directly transmitted from the hybrid musical instrument to the PDA without any keying-in so that the user feels the pairing work easy and speedy.