Pentatonic and Blues Scales: The Rock Mother Tongue

The idea

Scale	Formula	From A	Sound
Minor pentatonic	1 ♭3 4 5 ♭7	A C D E G	Rock lead guitar from Led Zeppelin to Nirvana
Major pentatonic	1 2 3 5 6	A B C♯ E F♯	Country, pop and classic-rock brightness
Blues scale	1 ♭3 4 ♭5 5 ♭7	A C D E♭ E G	Minor pentatonic plus the “blue note”

Minor pentatonic is natural minor with its two sensitive notes removed: the 2 and the ♭6, the notes that create half steps. With no half steps left, it is almost impossible to play a wrong note.

Major pentatonic does the same thing to the major scale: it removes 4 and 7. The shapes are identical to minor pentatonic with the root moved. A minor pentatonic and C major pentatonic are the same five notes, exactly like relative keys.

The blues scale adds the ♭5 to minor pentatonic. The ♭5 is a passing note: squeeze it between 4 and 5, bend into it, slide through it. Do not sit on it.

The deep skill. Pentatonic is not a beginner scale. It is a skeleton. Professionals play pentatonic and add to it: the 2, the 6, the ♭6, chromatic passing notes. They decorate a strong frame. Beginners play seven-note scales and get lost. Switch the explorer between minor pentatonic and natural minor to see the two added notes.

On your instrument

You probably know “the box”: A minor pentatonic at the 5th fret. Now go further.

• Learn all five boxes, and more importantly the diagonal paths that connect them up the neck. These are the sliding shapes every rock player uses to travel from the 5th fret to the 12th in one phrase.
• Find the roots in every box. There are two or three in each. Start and end phrases on them until you can find them without looking.
• Mix major and minor (the B.B. King and Eric Clapton move). Over a blues in A, alternate A major pentatonic (sweet) and A minor pentatonic (tough). Rule of thumb: major pentatonic over the I chord, minor pentatonic over the IV and V chords.
• Bends are part of the scale. The classic targets are 4 bent up to 5, ♭7 bent up to 1, and ♭3 bent slightly sharp toward the major 3rd (the “blues curl”).

A 12-bar blues in A to play over:

Worked example

A riff in E minor pentatonic on the two lowest strings, palm-muted, straight 8th notes. Three bars are identical and the fourth changes its ending:

Bars 1, 2, 3     1 & 2 & 3 & 4 &
A|-----------------------0-2-----|
E|---------------0-0-3-0-----3-0-|
                 1 1 ♭3 1 4 5 ♭3 1

Bar 4            1 & 2 & 3 & 4 &
A|-----------------------0-2-5-7-|
E|---------------0-0-3-0---------|
                 1 1 ♭3 1 4 5 ♭7 1

The variation climbs to the ♭7 and the octave instead of falling back. Repeating an idea three times and changing the fourth is most of what riff writing is. Module 5 turns this into a system.

Exercises

1. Two notes per bar. Loop the 12-bar blues above and solo using at most two notes in each bar. This forces phrasing instead of noodling.
2. Write a 4-bar riff in E minor pentatonic on the bottom two strings, palm-muted. Then write variation B by changing only the last bar.
3. Work out the first four bars of any pentatonic solo you love, by ear, roughly. Label the degrees.
4. Play the same lick in A minor pentatonic and then three frets lower in A major pentatonic, over an A chord. Notice that the notes that sounded tough now sound sweet.

Common mistakes

• Living in one box. The first box is a room. The neck is a house.
• Sitting on the blue note. Held for a whole bar, the ♭5 sounds like a mistake. Passed through, it sounds like the blues.
• Running the scale up and down. A scale is an alphabet. Nobody wants to hear the alphabet.

Check yourself