HW Diminished Scale

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This scale is known as the HW diminished scale. It is formed by alternating half steps and whole steps, beginning with a half step. It contains eight distinct pitches. The notation above uses enharmonic spellings to emphasize how the scale fits a dominant seventh chord. It outlines a dominant seventh chord with flat and sharp ninths, and a raised eleventh:

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The chord is normally specified with a flat fifth rather than sharp eleventh, but the scale is spelled as it above is to avoid skipping the fourth while containing two fifths. The chord is notated as 7b9b5 or simply 7b9. The HW diminished scale is the natural choice over this chord. Here is an example of a line based on the HW diminished scale:

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Note this scale differs from the altered scale only in that the HW diminished scale contains a perfect sixth and major sixth in place of the augmented fifth of the altered scale:

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Thus, these scale are sometimes used interchangeably.

The pattern of alternating half and whole steps in this scale repeats at every other note. Thus, for example, the scale built on C is identical to the scale built on D#, F#, or A:

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There are four repeat points in the scale, and therefore there are only 12/4 = 3 different HW diminished scales: the scale starting on C, C#, or D. The other HW diminished scales are modes of these. For example, the F HW diminished scale is identical to the D scale:

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Here is an example of a repeating pattern that exploits the symmetry of the scale:

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Copyright 2000 Outside Shore Music
Authored by Marc Sabatella

HW Diminished Scale