Abstract: An input device inputs waveform number data containing number assigned to a special-effect waveform to be selectively generated. A memory unit is connected to the input device in order to store the waveform number data as input by the input device into the memory unit. A memory selector supplies memory select data to the memory unit for reading out the waveform number data from the memory unit. A waveform code converter converts the waveform number data, as read out from the memory unit, into waveform codes, which correspond to the special-effect waveform to be selectively generated. A special-effect waveform generator generates a special-effect waveform signal in response to the waveform code applied from the waveform code converter. The generated special-effect waveform signal corresponds to the waveform code applied.