Harmonic table note layout

This note layout created by Euler is utilised in Neo-Riemannian theory to geometrically model its musical ideas.

A similar keyboard was developed by Larry Hanson [4] in 1942 for use with a 53 tone scale but turns the fifth sideways and the major third to the right and up.

The modern layout was proposed in 1983 by inventor Peter Davies, who obtained an international patent for its use in instruments in 1990.

There are a large number of isomorphic note-assignments possible; however, the Harmonic Table format is unusual in the musically important intervals it uses: Ergonomically, the harmonic table format is exceptionally compact: all notes of the major and minor scales fall under the fingers, and all common chords can be played with one or two fingers.

This key layout has attracted the attention of numerous professional musicians, including Brian May and Jordan Rudess who find that it gives them a novel view of music, which is reportedly very useful in composing.