Between 2006 and 2014, I built every Tonal Plexus keyboard by hand, and sold them to musicians around the world. During 2015 I took a break from this work. From January to July of 2016, I offered Tonal Plexus TPX and UPLEX keyboards as DIY projects. Several original Tonal Plexus prototypes were also sold. Tonal Plexus keyboards have appeared in print everywhere from Keyboard magazine to the New York Times and various publications in Europe. There are fewer than 100 Tonal Plexus keyboards in existence.

In the whole history of music, no other instrument has ever been designed to do what the Tonal Plexus does. I wrote this short article at the request of the late Bob Gilmore for the Journal of the Fokker Institute to explain what the keyboard is all about.

The keyboard represents a theory of music called the H-System, which can be found at the following link.

Here are the user manuals for the TPX line of Tonal Plexus keyboards which I built 2007-2014.

I often receive emails asking when I will build the keyboards again. I don't have an answer to this yet, but rest assured that plans and designs are in the works, and the keyboards are not dead or dying by any means. If you would like to have a Tonal Plexus, please tell me so, so I can keep you informed. If you are on facebook, please also visit the H-Pi Instruments facebook page. I normally post on the facebook page when I write something for the H-Pi Instruments blog. Since July 2016 I have been writing a series of blog entries telling the story of how the Tonal Plexus came to be, and where it is headed. To find out more, please take a look. I sincerely appreciate your interest and support. — Aaron Andrew Hunt