To produce desired musical tones when a player makes a gesture.

Foot sensors among sensors 5 are provided with impact sensors at the tones and heels. A CPU 1 executes processing to produce tongs by having the musical tones corresponding to the toe sensors formed by a sound source circuit 10 when the outputs of the toe sensors exceed prescribed values. This CPU executes the processing to produce the musical tones corresponding to the toe sensors when the outputs do not exceed the prescribed values but are at the level larger than the heel sensor outputs. As a result, the production of the undesired musical tones is prevented even if the undesired sensor outputs are emitted from the heel sensors when the player makes the gesture to apply impact only to the tone sensors.