Kawai CA1000 Owner's Manual page 37

If you own a "GM" sound module you'll probably want to use it as your
multi-timbral module instead of the CA piano. If you have a hardware
sequencer or personal computer but do not own another sound module,
you can enjoy sixteen-part multi-timbral capability with only the CA piano.
MIDI may seem a little difficult to work with at first, but once mastered it
offers many new and exciting ways to enjoy music.
While this manual avoids going into too much detail regarding the technical
aspects of MIDI such as "system exclusive data", for those who are more
familiar with MIDI or want to be, this manual provides technical MIDI
information and a MIDI Implementation Chart, on page 76 and 77.
TUTORIAL: USING MIDI 33