Whole Tone Scale

In music, a whole tone scale is a scale in which each note is separated from its neighbors by the interval of a whole step. There are only two complementary whole tone scales, both six-note or hexatonic scales:

The whole tone scale has no leading tone and because all tones are the same distance apart, "no single tone stands out, the scale creates a blurred, indistinct effect". This effect is especially emphasized by the fact that triads built on such scale tones are augmented. Indeed, one can play all six tones of a whole tone scale simply with two augmented triads whose roots are a major second apart. Since they are symmetrical, whole tone scales do not give a strong impression of the tonic or tonality.

The composer Olivier Messiaen called the whole tone scale his first mode of limited transposition. The composer and music theorist George Perle calls the whole tone scale interval cycle 2, or C2. Since there are only two possible whole tone scale positions (that is, the whole tone scale can be transposed only once), it is either C20 or C21. For this reason, the whole tone scale is also maximally even and may be considered a generated collection.

Due to this symmetry, the hexachord consisting of the whole-tone scale is not distinct under inversion or more than one transposition. Thus many composers have used one of the "almost whole-tone" hexachords, whose "individual structural differences can be seen to result only from a difference in the 'location,' or placement, of a semitone within the otherwise whole-tone series." Alexander Scriabin's mystic chord is a primary example, being a whole tone scale with one note raised a semitone, with this alteration allowing for a greater variety of resources through transposition.