An electronic musical instrument comprises a tone generator for generating a plurality of different digital waveform signals corresponding to different timbres, and a device for setting a plurality of ranges defined by two parameters, a first one of the parameters being a pitch parameter and a second one of the parameters being a key touch parameter. The parameters vary according to the musical performance, and a range for the pitch parameter in combination with a range for the key touch parameter respectively designating one of the plurality of different digital waveform signals having different timbres. An input device is provided for inputting the two parameters according to a musical performance. A judging device judges a respective range to which each of the inputted two parameters belongs, and a selector selects one of the plurality of digital waveform signals from the setting device corresponding to a judged result to generate one of the plurality of different digital waveform signals from the tone generator, the plurality of different digital waveform signals thereby being selectively generated in order to output a sound having a corresponding timbre in response to the two parameters thus inputted.