This video captures a performance of Bach's C Major Prelude and Fugue (opening) played in Just Intonation on a Tonal Plexus keyboard.

The H-Pi Tonal Plexus keyboard offers 211 keys per octave, providing the finest discrete control of tuning available on a MIDI keyboard.

This is an experimental performance which uses pure 3rds and 5ths, natural 7ths in dominant chords, and harmonics reaching the 17-Limit in diminished chords. In several places, a common tone can be heard to 'bend' from one chord to the next (usually in ii-V progressions) where a pitch has to move by a septimal comma; the pitch is changing in real time by JND steps.

Details on the Tonal Plexus, along with more performance videos, are available at the H-Pi site.

Link:

• H-Pi

James Lewin
Twitter @podcasting_news