Prometheus

One note away from the whole tone scale

Write the whole tone collection from C — C D E F♯ G♯ A♯ — then lower nothing and raise nothing except the fifth degree, moving G♯ up to A. The result is C D E F♯ A B♭, the Prometheus scale. Five of the six notes are unchanged.

That single move changes the character completely. The whole tone scale is perfectly uniform and therefore has no centre at all; shifting one note breaks the symmetry, and the twelve transpositions of Prometheus are all distinct where the whole tone scale had only two. The scale keeps the floating quality and gains something to hold on to.

Stacked in fourths: the mystic chord

Scriabin voiced these notes as C F♯ B♭ E A D — a stack of fourths rather than the thirds Western harmony is written in. The fourths are not identical: an augmented fourth, a diminished fourth, an augmented fourth, then two perfect ones. It is that mixture, not fourths as such, that gives the chord its particular density.

Voicing in fourths matters more than it sounds. Because notation is a grid built from thirds — the lines of the treble staff are E G B D F — a chord written in fourths resists being read as a stack with a root at the bottom, and that resistance is the practical reason the chord has been argued about for a century.

What is actually inside the six notes

Running the six degrees through our harmonic analysis gives a family formula of 1×1: exactly one major triad (D) and one minor triad (Am) across the whole scale, plus three augmented and one diminished. Two degrees carry no standard triad at all. On C — the note Scriabin put in the bass — there is no major, minor, diminished or augmented triad; only C–E–B♭, a seventh with the fifth missing, and on E only a stack of fourths, E–A–D.

The remaining notes divide into two shapes. B♭–D–F♯ has spacings of 4, 4 and 4 semitones: an equilateral triangle, which mathematically has no root, since rotating it changes nothing and all three vertices are equal. A–C–E has spacings of 3, 4 and 5 and a perfectly clear root. Half of this sonority has a root and half of it does not.

Why it has so many names

Because a chord symbol needs a bottom note and this chord supplies six candidates, each degree produces a defensible name: C13♯11 from C, D9♭13 from D, B♭+maj7 from B♭, and readings on E, F♯ and A besides. None of them is wrong; each describes a different step of the same object.

The most common of them is also the least literal. C13♯11 spells out seven notes — C E G B♭ D F♯ A — and only six are sounding, since the G is absent. No standard chord symbol covers all six: the largest that fits covers five. The sonority falls between two adjacent sizes of the vocabulary, which is a plainer reason for the disagreement than any question of theory.

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