Lesson 23 - The Blues Scale

The hexatonic, or six-note, blues scale consists of the minor pentatonic scale plus the ♭5th degree of the original heptatonic scale. This added note can be spelled as either a ♭5 or a ♯4. A major feature of the blues scale is the use of blue notes; however, since blue notes are considered alternative inflections, a blues scale may be considered to not fit the traditional definition of a scale. At its most basic, a single version of this blues scale is commonly used over all changes (or chords) in a twelve bar blues progression. Likewise, in contemporary jazz theory, its use is commonly based upon the key rather than the individual chord. The evolution of this scale may be traced back to Asia (pentatonic major) through native North America (pentatonic minor) with the addition of the flat-5 blue note (slave trade/Africa). Greenblatt defines two blues scales, the major and the minor. The major blues scale is 1, 2,♭3, 3, 5, 6 and the minor is 1, ♭3, 4, ♭5, 5, ♭7. The latter is the same as the hexatonic scale described above.