Blues scales

There is no unique blues scale, but several combinations of notes which have a blues sound. These three blue notes are :

  • b10 
  • b
  • b5 / #11

We can classify the blues scales this way :

Hexatonic scales or six-notes blues scales.

  • The minor blues scale is the minor pentatonic scale (1-b3-4-5-b7) including a flat ninth (b5). This is the most widely used of the blues scales. It is built with a root (1), a minor third (b3) also considered as flat eleventh (b10) or sharp ninth (#9), a fourth (4 or 11), a flat fifth (b5 or #11) which is the blue note and a minor seventh (b7).
  • The minor blues scale with a major 3rd. (1-b3-3-4-5-b7)
  • The minor blues scale with a seventh. (1-b3-4-5-b7-7) or  (1-b3-4-b5-5-7)
  • The voodoo blues scale (1-b3-4-b5-5-6).
  • The major blues scale is the major pentatonic scale (1-2-3-5-6) with an added b3 also named b10. It consists of a root (1), a second (2), a minor third, the blue note (b3 or b10), a major third (3), a perfect fifth and a major sixth (6).

These previous blues scales are the most played in jazz and blues music.

Heptatonic scale

This composite blues scale consists of eight notes, including the three blue notes. Formula is 1-b10-3-11-b5-5-b7-7.

Nonatonic scale

The composite blues scale or Mixolydian blues scale or mixo blues scale is built with nine notes. As its name implies, it is a mix of the minor blues scale (1-b3-4-b5-5-b7) and the Mixolydian mode 1-2-3-4-5-6-b7 (or the major pentatonic scale). This scale combines major & minor pentatonic sounds, here is the formula : 1-2 (9)-b10 (or #9)-3-11(4)-b5(#11)-5-13(6)-b7.