My explanation of the H-Pi Instruments Tonal Plexus microtonal keyboard

I own one of the first Tonal Plexus keyboards made by H-Pi Instruments. This unique MIDI controller opens new possibilities in music. It is far from the first alternative keyboard, but it is one of the first with this degree of pitch capability and flexibility. I have one of the first ones built in 2008. I have played around on it, and the potential is overwhelming (though there are some limits — it isn't velocity sensitive per key, though a pedal can adjust overall velocity). I've been slow to really put in the time to explore it all. In this video, I give my perspective on how this thing works (using a relatively harsh pure tone to make the demonstration clear — but it can access any MIDI-controllable sound). This video also teaches some basic ideas about pitch and music. For more on the keyboard, including pages about the music theory behind it, history of related instruments, and even a FREE software version along with other interesting things, check out the maker's site at h-pi.com. This video was made with the keyboard, REAPER software, and the free Automat soft-synth for mac. Thanks to Doug Jones for the camera work. One note: the tuning I use on my keyboard is a customized C-based extended just intonation that is precisely tuned (different from the keyboard's default 205-note temperament which offers just intonation approximation very close for some notes and 3-cents error at most, but the difference is harmonically audible when using very steady and pure harmonic timbres).