Tri-Chromatic Keyboard Layout

Roy Pertchik designed a “Tri-Chromatic Keyboard” layout that he uses on a custom-built vibraphone.  It has an isomorphic, symmetrical, 6-6, Janko-style, layout and a rotating three-color pattern that highlights minor thirds and diminished chords.  He also has a note naming system along similar lines.  The instrument layout and note names were inspired by Barry Harris’ approach to Jazz theory and harmony and are designed to complement it.

Here is an image showing the isomorphic 6-6 layout with its rotating three-color pattern.


The green outlines highlight one of the two scales that are central to the Barry Harris approach: the Maj6th/Diminished. It is formed by interlacing a Major 6th chord with a Dimininished chord, which yields a traditional major scale with a chromatic note added between the 5th and 6th scale degrees.  (For example, a C major scale with a G-sharp/A-flat note added.)  In this image the red circles are the Diminished chord and the other circles inside the green outlines are the Major 6th chord.

Here are a couple of videos where Pertchik presents his vibraphone:

Shorter 6 minute introduction:

Longer presentation at Stanford University:

Here are two handouts (PDFs) from the Stanford presentation:
CCRMA Outline 02
I-IV-V in Bb

More on the Barry Harris approach to jazz harmony can be found in these two articles: