mystic chord or Prometheus chord

mystic chord

In music the mystic chord or Prometheus chord is a complex six-note chord, scale, or pitch collection, which loosely serves as the harmonic and melodic basis for some of the later pieces by Russian composer Alexander Scriabin. Scriabin, however, did not use the chord directly but rather derived material from its transpositions.

It consists of the pitch classes: C, F♯, B♭, E, A, D. This is often interpreted as a quartal hexachord consisting of an augmented fourth, diminished fourth, augmented fourth, and two perfect fourths. However, the chord may be spelled in a variety of ways, and it is related to other pitch collections.