a friend gave me an old master keyboard, a roland pc-200. i decided to transform it into a keytar, a strap-on keyboard. i've used two guitar/bass knobs for strap and two buttons (bending up and modulation) and one swich (for permanent modulation). it's easy to do bendings with the joystick (even if it has no neck like other keytar) but with the button it's nicer.
bending up button
modulation switch (on/off)