Each of a plurality of pad devices that can be moved independent of each other includes: a sensor section for detecting a strike; and a transmitting section for transmitting operation information according to an output of the sensor section with wireless communication. A receiving section is provided in connection with a sound generating device to receive the operation information transmitted from each of the pad devices with wireless communication. The sound generating device generates a musical tone signal in accordance with the received operation information. A pad location detecting section detects a location of each of the pad devices. The sound generating device carries out tone generation control, for example, sound image localization control, for the musical tone signal generated in correspondence with each of the pad devices in accordance with the location of each of the pad devices detected by the pad location detecting section.