octatonic scale
A symmetrical eight-note scale alternating whole steps and half steps, producing a dark, ambiguous harmonic color.
In Depth
The octatonic scale (also called the [diminished scale](/term/diminished%20scale)) alternates between whole steps and half steps through eight notes before repeating at the octave. This creates a highly symmetrical structure — only three distinct octatonic scales exist, each transposable at the minor third. The scale contains within it four diminished triads, four augmented triads, and a wealth of other harmonic possibilities, making it extraordinarily versatile. Rimsky-Korsakov was among the first to exploit the scale systematically (it is sometimes called the Rimsky-Korsakov scale in Russian theory), using it to evoke magical or supernatural elements. Stravinsky, Bartók, and Messiaen all made extensive use of octatonic materials, and the scale is fundamental to jazz improvisation over diminished and dominant chords. Its combination of chromaticism and symmetry gives it a restless, questioning quality distinct from both major/minor tonality and pure atonality.
Messiaen called the octatonic scale his "second mode of limited transposition" and used it throughout his compositions to evoke what he described as "the charm of impossibilities."