Jazz Scale - Altered Dominant Scale

Altered Dominant Scale

The altered dominant scale, also loosely called the altered scale, is so named because all the scale members that can be altered relative to the basic dominant scale (the Mixolydian mode), without losing the dominant quality, are altered. The scale includes both altered ninths (raised and lowered), and both altered fifths (raised and lowered). Starting on C, it contains the notes: C, D♭, E♭, F♭, G♭, A♭ and B♭. The altered fifths coincide enharmonically with the sharp eleventh and the flat thirteenth which would also be considered altered relative to their Mixolydian forms. The tonic, major third (as a diminished fourth), and dominant seventh are retained as essential to the dominant quality.

The scale can also be understood as a mode of the ascending melodic minor scale starting from the 7th scale degree. For a C7 chord, the C♯ melodic minor scale starting from B♯ (C enharmonically) produces the C altered dominant scale enharmonically.

This scale is also called the superlocrian scale, as it is indeed reminiscent of a locrian scale with a flattened 4th, but it is usually regarded as that of major quality.

Another name for this scale is the diminished-wholetone scale because the first tetrachord is that of a (half, whole) diminished scale and the second tetrachord is whole-tone (or locrian).