The Key-Based Instrument Controller message is intended to be a standard method of providing individual key-based instruments with the same performance control that is available for Channel-based instruments.
ca23 Key-based Instrument Controller SysEx Message.pdf The Key-Based Instrument Controller message is intended to be a standard method of providing individual key-based instruments with the same performance control that is available for Channel-based instruments. Specific responses to this message may be defined in a separate recommended practice, such as General MIDI 2.