Use As A Keyboard Instrument; Playing The Keyboard - Casio KX-101 Operation Manual

Use as a Keyboard Instrument
@ Playing the Keyboard
Set the FUNCTION selector to KEYBOARD.
Always set to KEYBOARD when using the KX-101 as a keyboard
instrument.
2 Set the keyboard mode to "PLAY".
Set the CHANNEL to POLY or MONO.
MONO: The keyboard can be played as a monophonic (single voice)
instrument.
Now, try playing the keys.
* The sound has been set to PIANO 1,
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