Pentatonic and blues scales

Also called pentatonic scale, blues scale, or five-note scale

A pentatonic scale has five notes instead of seven and no half steps, so it is hard to land on a clashing note. The blues scale is the minor pentatonic plus one extra “blue” note, the flat 5th.

What are the pentatonic scales?

Penta means five. Take a major scale and leave out the two notes that make its half steps, the 4th and the 7th, and five notes remain: 1 2 3 5 6. In C that is C D E G A, the major pentatonic scale. With no half steps inside it, no two of its notes grind against each other.

C major pentatonic: C D E G A. Every gap is a whole step or a step and a half.

The minor pentatonic is the minor scale without its 2nd and 6th: 1 ♭3 4 5 ♭7. In A that is A C D E G, exactly the five keys of C major pentatonic counted from the sixth note, the same way A minor shares C major’s notes. Learn one set of five and you know both.

A minor pentatonic: A C D E G. The same five letters as C major pentatonic, started from A.

What is the blues scale?

Add one note to the minor pentatonic, the flat 5th, and you have the blues scale: 1 ♭3 4 ♭5 5 ♭7. In C that is C E♭ F G♭ G B♭. The G♭ is the added blue note. It sits a half step from the 5th beside it, and players slide through it or lean on it for a moment rather than rest there.

C blues scale: C E♭ F G♭ G B♭. The green key is the added ♭5; the rest is C minor pentatonic.

Why do they work for improvising?

Two reasons. Fewer notes means fewer wrong ones, because these scales leave out the notes most likely to clash with a chord. And in a twelve-bar blues, the minor pentatonic and blues scale built on the key’s tonic work over all three chords even as the chords change; the ♭3 rubbing against a major chord is the sound of the style, not a mistake. Over a major-key pop loop such as I–V–vi–IV, the key’s major pentatonic plays the same safe role.

The easiest place to hear it is the black keys. Take G♭ as home and they are G♭ major pentatonic (G♭ A♭ B♭ D♭ E♭); take E♭ as home and they are E♭ minor pentatonic (E♭ G♭ A♭ B♭ D♭). Improvise on black keys alone and almost any choice sounds like music.

The five black keys, G♭ up to G♭: major pentatonic with G♭ as home, minor pentatonic with E♭ as home.

Common questions

What is the difference between a major and a minor pentatonic scale?

They hold the same five notes with a different home. Major pentatonic (1 2 3 5 6) sounds open and bright, minor pentatonic (1 ♭3 4 5 ♭7) sounds darker and bluesier. The minor one starts on the major one’s sixth note.

What is a blue note?

It is one of the lowered notes that give the blues its sound: the ♭3, ♭5 and ♭7. The blues scale adds the ♭5 to the ♭3 and ♭7 the minor pentatonic already has. Singers and guitarists bend them. A pianist cannot bend a key, so the effect is made by sliding in from a neighboring key with a quick grace note.

Why do the black keys make a pentatonic scale?

Counting from F♯, the five black keys are 2, 2, 3, 2 and 3 half steps apart, which is exactly the major pentatonic pattern, so any mix of them sounds consistent.