To provide an electronic keyboard musical instrument for performing key depression speed detection and key release speed detection with a small circuit scale.

The electronic keyboard musical instrument includes: a plurality of keys and a plurality of key switches respectively disposed for those keys. The electronic keyboard musical instrument includes: key speed detection means for detecting the speed of the corresponding key by a counter which accumulates a value each time the key passes the key switch; sound production control means for controlling the sound volume and/or tone color of a musical sound to be produced in accordance with the key depression speed and key release speed detected by the key speed detection means; and dynamic range changing means for changing accuracy with which the key depression speed and key release speed are detected by the key speed detection means. Thus, it is possible to perform key depression speed detection and key release speed detection by using a type of counter whose valid range is different.