Posted by: sebion | January 10, 2012

Polyphonic Aftertouch

It has been a long time since my last upload but the fruits of my recent work on EPiCK seem to justify that pause. As promised it is now time to introduce the polyphonic aftertouch (PAT) feature. In order to help the keyboarder training to use this function I’ve integrated a bargraph visualisation into my setup. It has a basic hand recognition feature – the screen is divided into a left and a right section each corresponding to the accordant hand  – to show you which fingers depresses what key how much and utilizes space characters to fairly depict the played chords.

In this video you see the visualization on my blue display and hear a guitar synthesizer which has been setup to correspond to PAT data by adjusting the note pitch by a maximum value of 45 cent at an aftertouch value of 127. To increase the effect I also added a slight PAT-controlled volume change of about 4dB to the fx chain. So the sound is basically supposed to imitate the sound of a clavichord which is the oldest known keyboard instrument that actually gives the player the ability to change the note pitch by the amount of pressure applied to the depressed key. I has a sound that is in my opinion somewhere between a guitar and a harpsichord and it has touch response of course. If you’re interested in this historical instrument you can see how it works on  and you can listen to a homemade instrument at



  1. This site has got a lot of really helpful stuff on it. Thanks for sharing it with me.

  2. No way! Ha ha ha. I’ve been waiting for some time for something like this. Poly AT is brilliant and so underrated. I would *love* to retro fit a synth with your kit. And a piano too, of course, lol…

    If you would like, I can raise awareness of this particular feature — there is a small but passionate crew of PAT lovers. Although few people have tried a version which was properly implemented, most of them did love it. Please see this through to production, and count me extremely interested. Respect.

  3. would love to see the code you wrote – that would help me with my project.


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