Confession #40 - Pentatonic Scales (Part 1)

Pentatonic scales are very commonly used in rock and roll, so you'll want to have a good understanding of them. Fortunately, they are not that difficult to understand or to play.  That's one of the reason for their popularity.

THE MAJOR PENTATONIC SCALE

Penta comes from the Greek language, and means 5, so penta-tonic means 5 tones  Thus a pentatonic sale has, yes you guessed it, 5 tones.

Which 5 tones you ask?  Well, take the C major scale (see Confession #8 - Learn the Major Scale!) and leave out the F and the B and you get the C major pentatonic scale:

[The numbers below the note names are the scale formula (see Confession #27 - Learn the Minor Scale!)]


C Major Scale

C - D - E - F - G - A - B - C
1   2   3   4   5   6   7   8
  W   W   H   W   W   W   H

The numbers below the note names are the scale formula (see Confession #27 - Learn the Minor Scale!)


C Major Pentatonic Scale

C - D - E - - - G - A - - - C
1   2   3       5   6       8
  W   W    H+W    W    W+H

Major Pentatonic Pattern #1

You may have already learned this pattern.  If not, take the time to learn it as Pattern #1 is very commonly used.

Major Pentatonic Pattern #1
(Click to Enlarge)

Observe that the root note C is at the 7th fret of your sixth string.  The A at the 5th fret of the sixth string is part of the scale, but I've shown it in dashed lines as it is below the root note.


THE MINOR PENTATONIC SCALE

Let's do the same thing again, but this time start with the A minor scale (see Confession #39 - Back to the Minor Scale!), which is the relative minor scale to the C major scale.

A Minor Scale

A - B - C  - D - E - F  - G  - A
1   2   3b   4   5   6b   7b   8
  W   H    W   W   H    W    W


A Minor Pentatonic Scale

A - - - C  - D - E - -  - G  - A
1       3b   4   5        7b   8
   W+H     W   W    H+W     W


Minor Pentatonic Pattern #1

Again, this pattern will probably look familiar.

Minor Pentatonic Pattern #1
(Click to Enlarge)

Observe that the root note A is at the 5th fret of your sixth string.

I've also shown the Am pentatonic extended box.  We'll discuss where these notes come from in a future confession.  For now, ignore the notes in the dashed lines.

You're probably thinking to yourself, "It's the same pattern as the major pentatonic scale!"  And you would be correct.  The A minor pentatonic scale is the relative minor scale to the C major pentatonic scale, so they do use the same notes.  The difference is which note you treat as the root note of the scale.
So how do you know which scale is which?  If you want to play the minor pentatonic scale, then the root note is under your index finger. If you want to play the major pentatonic scale, then the root note is under your fourth finger.  Note that minor and index both have the letter i in them.  This is the trick to remembering which scale is which.


OBSERVATIONS

Observe that there are only two notes per string, which makes these pentatonic scale patterns easy to play.  This is part of the reason they are so popular!

Observe that by eliminating the notes F and B, we eliminated the half steps from the standard major and minor scale.  If you can remember this fact, then you can easily build a pentatonic scale in any key,  Write out the major or minor scale for that key, and then eliminate the half steps. Boom! There's the pentatonic scale. That's easier then remembering the scale formula.

Next Week's Confession - 12 Bar Blues! 

Confession #27 - Learn the Minor Scale!

In Confession #8 - Learn the Major Scale! we learned the major scale, how it consists of a sequence of whole steps and half steps, and how it is the sound of do-re-mi-fa-so-la-ti-do.  In this confession, we'll learn the minor scale.

The Minor Scale

Like the major scale, the minor scale consists of a pattern of whole steps and half steps.  However, it uses a different pattern.  The minor scale pattern goes like this:

W-H-W-W-H-W-W

...where W means a whole step and H means a half-step.  

Let's build a minor scale in the key of C.  Starting on C and applying the minor scale pattern gives us the following notes:

C-D-Eb-F-G-Ab-Bb-C

If you jump ahead to the section below called On the Fretboard, there are two movable minor scale patterns you can practice, but I'm hoping you'll stick around for the rather lengthy music theory discussion that comes next.

Scale Formulas

In a minute we'll compare the major scale and the minor scale, but first let's learn about scale formulas. A scale formula is simply a series of numbers used to describe a scale.  The most basic scale formula is the major scale formula, which is written as follows:

1 - 2 - 3 - 4 - 5 - 6 - 7 - 8

The number 1 signifies the root note of the scale.

This formula implicitly means the pattern of whole steps and half steps that make up the major scale, like this:

1 - 2 - 3 - 4 - 5 - 6 - 7 - 8

W   W   H   W   W   W   H

If we are using any scale other than the major scale, we need to change this scale formula to describe the new scale by adding sharps (i.e. #) or flats (i.e. b) to the numbers in the scale formula.

This point is very important to understand, so its worth repeating:

The scale formula 1-2-3-4-5-6-7-8 refers only to the major scale!

Comparing the Major and Minor Scale 

To illustrate the previous point, let's compare the C major scale to the C minor scale.  

C Major

Here is the C major scale with the scale formula written below the notes of the scale:

C - D - E - F - G - A - B - C

1   2   3   4   5   6   7   8

W   W   H   W   W   W   H

C Minor

Here is the C minor scale with the scale formula written below the notes of the scale:

C - D - Eb - F - G - Ab - Bb - C

1   2   3b   4   5   6b   7b   8

W   H    W   W   H    W    W

The C minor scale contains many of the same notes as the C major scale, however 3 of the notes are different.  The notes E, A and B in the major scale all have to be lowered a half step, and thus become Eb, Ab and Bb.

Thus when writing out the scale formula for the minor scale, we have to add a flat symbol to the 3rd, 6th and 7th scale degrees.


Understanding Scale Formulas

To understand scale formulas, it is critical to understand that they are all defined with reference to the major scale formula.

Let's look at the minor scale formula in isolation.  It is:

1 - 2 - 3b - 4 - 5 - 6b - 7b - 8

Okay, so I am supposed to play a flat 3rd, 6th and 7th, which I do by lowering each of the 3rd, 6th and 7th one half step (one fret on the guitar).  But to do this, first I have to know what the 3rd, 6th and 7th are!!!

To find them, you have to refer to the major scale of whatever key you happen to be playing in.  As shown above, in the key of C the 3rd, 6th and 7th are the notes E, A and B.  Therefore the flat 3rd, 6th and 7th are Eb, Ab and Bb.

To further illustrate this point, let's build a minor scale in the key of G.

First, we need to know what the G major scale is.

G - A - B - C - D - E - F# - G

1   2   3   4   5   6   7    8

W   W   H   W   W   W    H

Now take the minor scale formula and adjust the notes in the G major scale to get the G minor scale:

1 - 2 - 3b - 4 - 5 - 6b - 7b - 8

G   A   Bb   C   D   Eb   F    G

W   H    W   W   H    W    W

On the Fretboard

Here are two movable minor scale patterns, one starting on the 4th string and the other starting on the 6th string.  Both are shown in the key of C minor,  but you can change the key by moving the patterns up and down the fretboard.

Starting on the 4th String

Minor Scale Pattern
Root on 4th String

Fingering for this pattern is 1-3-4, 1-3-4, 2-4 where finger 1 is your index finger and finger 4 is your pinky.

Starting on the 6th String

Minor Scale Pattern
Root on 6th String

Fingering for this pattern is 1-3-4, 1-3-4, 1-3 where finger 1 is your index finger and finger 4 is your pinky.

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Next Week's Confession - Palm Muting! (Part 2)