Korg PA1000 User Manual page 58

46| Playing and singing
Using the joystick
Moving the joystick left of right usually changes the Sound's pitch. Moving
it forward usually trigger modulation, but this depends on the selected
Sounds. With the electro-mechanical organs, pushing the joystick forward
changes the rotary speaker's speed. What it does when pulled back depends
on the selected Sounds. Just experiment!