An electronic percussion musical instrument comprises a plurality of playing pads for playing music by striking the face of each pad. The pads are configured to provide ungrouped pad zones, each constituted by an individual playing pad and grouped pad zones, each constituted by combining plural playing pads into a grouped pad zone to work as an integral pad zone. Timbres of musical tones are allocated to the respective pad zones. A sequence of pad zones, each designating the allocated timbre, is set for a pad zone to represent a pad chain performance, so that plural music playing strikes on the same pad zone cause the generation of musical tones in the timbres allocated not only to the struck pad zone but also to the other pad zones in the order designated in the sequence for the pad chain performance on the struck pad zone.