Dampers provided in corresponding relation to a plurality of keys are each controlled in response to both an operation of a pedal and an operation of the corresponding key. One half region or half point is determined based on a plurality of half pedal regions or half pedal points, in a stroke of the pedal, specific to the individual dampers. Performance data instructing a pedal operation is generated and recorded on the basis of a stroke position detected in response to a pedal operation and the determined one half region or half point. For each of the keys, a key-damper half region or key-damper half point in a stroke of the key is identified in advance. Performance data instructing key operations is generated and recorded on the basis of the key-damper half regions or key-damper half points specific to the keys and stroke positions detected in response to key operations.