The blues scale is actually a 6 note scale and the scale is similar to the minor pentatonic/ major scale, but with an additional lowered fifth. The lowered fifth, also known as the "blue note", is essential in blues music.
Constructing The Blue Scale
From Major Scale: You can easily play this scale in any key by using the major scale as your starting point. Just note that the scale is built with this formular 1, b3, 4, b5, 5, b7, and 1 again.
First, play your major scale in whatever key you’re in. From there you can find the blues scale in whatever key you’re in by just following these easy steps:
- Move your 3rd note in the major scale down a half step to find the b3.
- Move your 5th note in the major scale down a half step to find the b5
- Move your 7th note in the major scale down a half step to find the b7.
- The rest of the notes (1,4, and 5) are the same pitches you would find in the major scale.
From Minor pentatonic Scale:They are the 5 notes of the minor pentatonic scale, plus one additional note.The note added is the diminished 5th (o5) measured from the scale tonic.
For example C minor pentatonic scale: C - Eb - F - G - Bb - C. With the addition of the diminished 5th-Gb, Produces the C Blues Scale: C - Eb - F - Gb - G - Bb - C