From CCRMA Wiki
This instrument uses the slorkian fret-based mapping to trigger notes. It has been modified to allow polyphony.
How to Play
Pressing keys triggers notes. Releasing keys releases notes. Simple. Clean. Effective. Gluten-free.
Moving the trackpad along the x-axis performs a filter sweep with a moderately high resonance.
Moving the trackpad along the y-axis detunes the sound.
Here is the chuck file. Note that you may use a mouse rather than the trackpad to give the instrument a different feel.