The blues scale is very similar to the minor pentatonic scale, except that it contains one extra note- the flattened fifth degree (b5). The scale formula is as follows;

1 b3 4 b5 5 b7 8(1)

If we compare this with the major scale, in this instance we will use Bb Major, and we can see how the pentatonic scales both major and minor are made, and form the basis for this scale.

Bb C D Eb F G A Bb

1 2 3 4 5 6 7 8(1)

The minor pentatonic scale has the formula; (1 b3 4 5 b7) giving us the following scale in Bb.

Bb Db Eb F Ab

1 b3 4 5 b7

The major pentatonic scale has the formula; (1 2 3 5 6) giving us the following scale in Bb.

Bb C D F G

1 2 3 5 6

The blues scale that is closely related to the minor pentatonic is often referred to as “the minor blues scale” as it contains all the notes of the minor pentatonic scale with the addition of the flattened fifth. Giving us the following notes:

Bb Db Eb Fb F Ab

1 b3 4 b5 5 b7

The blues scale that is closely related to the Major pentatonic is often referred to as “the major blues scale” as it contains all the notes of the Major pentatonic with the addition of the flattened third. Giving us the following notes:

Bb C Db D F G

1 2 b3 3 5 6

Both scales can be used in conjunction with each other or as extensions of each other implying a different tonality over the same chord or as individual scales implying a Major or minor tonality respectively. This relationship is similar to the relative major and relative minor relationship of the Major scale. It is the addition of the flattened tones in each scale that give a chromatic movement and that distinctive blues tonality that is so easily recognisable. The flattened 5^th is commonly called the “blue note” the combination of flattened tones and Major tones make the blues scale a highly versatile scale within musical harmony.