An electronic keyboard musical instrument capable of performing delicate sound board vibration control based on outputs generated individually for respective ones of transducers, thereby realizing production of natural sounds with sufficient volume, and an easy tone quality adjustment. A sound board is fixed to a frame, and the transducers are mounted to the sound board so as to be spaced from one another. In accordance with first and second performance signals generated in response to a key operation of a keyboard and a damper pedal operation, driving signals for the transducers are individually generated in consideration of characteristics and mounting positions of the transducers, and the driving signals are supplied to the transducers. The sound board is thereby caused to vibrate at a frequency varying according to a tone pitch, thus producing a musical tone and/or a damper tone.