Coltrane's Tone Circle
10 hours ago
- Coltrane's tone circle diagram is essentially the circle of fifths/fourths filled with chromatic scales, and he never explained it in writing.
- The article rebuilds the diagram as an interactive widget, with C as the default root and the outer ring moving by perfect fourths.
- The circle visualizes key relationships: neighboring keys share six of seven notes, while keys a tritone apart share only two.
- Stacking fourths creates quartal harmony and gives the circle its twelve positions; intervals like minor thirds and major thirds generate symmetric shapes.
- Symmetric shapes include the whole-tone hexagon, diminished 7th squares, augmented triad triangles, and tritone lines, each creating harmonic ambiguity and multiple possible roots.
- Diminished 7th chords form only three unique squares and can act as rootless dominant 7b9 substitutions, with four possible roots per square.
- Augmented triads form only four triangles; the augmented triad connecting Eb, G, and B underpins the key scheme of 'Giant Steps.'
- The 2-5-1 progression appears as neighboring steps clockwise around the circle, with guide tones resolving by half step.
- Tritone substitution replaces a dominant chord with another a tritone away, keeping the same guide tones and creating a chromatic bass line.
- Coltrane changes in 'Giant Steps' cycle through three keys a major third apart, approached by full and abbreviated 2-5-1 progressions.
- Modes can be visualized as a seven-note window sliding around the circle: moving clockwise adds flats and darkens the mode, while moving counter-clockwise adds sharps and brightens it toward Lydian.
- The circle concisely captures many fundamentals of jazz harmony, though extensions fit less clearly and Coltrane's full intent remains unknown.