What Is the Blues Scale? Learn How to Play Major and Minor Blues Scales

The blues scale is a popular scale based on various scales and numbers of pitches. As one of the most widely-played scales in music, the blues scale has evolved to include multiple expressions. Some players and musicologists argue that the blues scale has 6 notes; others say it has 7 notes. Some even advocate for a 9-note blues scale (which means 9 out of the 12 notes in Western music are available within the scale).

However, most people agree that the blues scale is a variation on the major and minor pentatonic scales, and those pentatonic scales are derived from the major scale and the natural minor scale. We can connect all these scales with a little bit of music theory.

The major blues scale comes from the major pentatonic scale, which comes from the full 7-note major scale. We call each note in the scale a scale degree. In the major scale, the scale degrees are very simple:

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

To put this in real-world terms, let’s consider the notes of a D major scale:

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

This means that D is the first scale degree (also called the “root”), E is the second scale degree, F# is the third scale degree, and so on.

In a major pentatonic scale, we eliminate the 4th and 7th scale degrees. This leaves us with:

1 - 2 - 3 - 5 - 6

And therefore a D major pentatonic scale includes the following notes:

D - E - F# - A - B

So how do you turn the major pentatonic scale into a major blues scale? You add what is known as “blue notes.” One way to work in a blue note is to add a flat 5th scale degree in addition to the natural 5th scale degree.

• In the key of D major, the 5th scale degree is A. The flat 5th is Ab.
• Therefore, in a D major blues scale, both A and Ab are available notes, and any Ab is usually directly followed by an A.

Another note you can add to a major pentatonic scale is a flat 3rd.

• In the key of D major, F# is the third scale degree. So a flat third would be an F.
• Therefore, in a D major blues scale, both F and F# are available notes, and the F is usually followed by an F#.

Other notes you can add to a major pentatonic scale to “blues” it up:

• The flat 7th (which would be C in the key of D major)
• The natural 7th (which would be C# in the key of D major), but only as a “passing tone” between C and D. Don’t linger on the natural 7th if you want to sound bluesy.

The fact is that you can make any note work in the major scale if you don’t linger on it too long. But one note to generally avoid is the flat 6th (which would be Bb in the key of D major). This note will really fight the major tonality.

The minor blues scale comes from the minor pentatonic scale, which comes from the full 7-note natural minor scale. Just like the major scale, the natural minor scale has 7 scale degrees. They are:

1 - 2 - b3 - 4 - 5 - b6 - b7

To put this in practical terms, let’s consider a G natural minor scale. Its notes are:

G - A - Bb - C - D - Eb - F

This means G is the root, Bb is the flat third, D is the fifth, F is the flat 7th, and so on.

To turn a natural minor scale into a minor pentatonic scale, we eliminate the 2nd and 6th scale degrees. This leaves us with:

1 - b3 - 4 - 5 - b7

And as such, the Gm pentatonic scale contains the following notes:

G - Bb - C - D - F

So how do we turn this minor pentatonic scale into a minor blues scale? As it turns out, in a lot of the same ways we altered the major pentatonic scale.

• You can add a flat 5th scale degree in addition to the natural 5th scale degree.
• You can add a natural 7th in addition to the flat 7th that’s already in the minor pentatonic scale. (But only use it in passing between the flat 7th and the root—so in the G minor blues scale, you can use an F#, but only to connect an F to a G.)
• You can add pretty much any note to the minor pentatonic scale except the natural 3rd. Within the G minor blues scale, this means you should not play a B natural. It will completely clash with the minor character of everything else you’re playing.
• But other than that natural 3rd, pretty much any note can work right if you know what you’re doing. It takes practice and trial-and-error, but you’ll be able to find which notes are the best ones to add on to a pentatonic scale.

Learn to play root position pentatonic and blues scales using a metronome.

• Start with quarter notes. Keep the metronome between 60-70 BPM.
• Bump the metronome. Once you can play the first position cleanly at speeds around 150 BPM, bump the metronome back down to 60-70 BPM.
• Eighth notes. In this position, play eighth notes.
• Practice other positions. Once you’re confident with the first position of the pentatonic and blues scales at varying speeds and note durations, practice playing the scales at the other positions.
• Switch to different keys. Continue using the metronome and practice in varying keys.
• Link the positions. Start linking the positions of the scales together as you play, so you can start at the lowest root note of a scale and play ascending scales all the way up the neck.

Study and learn the different positions of the pentatonic and blues scales as shown in the below diagrams. Stick to one key at first, until you’ve memorized the shapes for each of the positions.

Carlos Santana is a guitar legend. His career has spanned over 50 years, and, while his music is eclectic, foundationally it always comes back to the blues. “If you can play some blues you can play anything. If you can’t play the blues you should do another thing as a profession, you know?”

Here are some ways that Carlos keeps his blues playing fresh:

• Use lots of 7ths and 9ths. Carlos often plays 7th chords instead of triads and on major chords, he often embellishes with a #9 (for instance, a G added into an E major chord).
• Bend strings. Sometimes Carlos will bend a #9 up by a half-step, and suddenly it becomes the third in a major triad. Sometimes he’ll bend a #11 note up a half-step, and it becomes the 5th in a major triad. These familiar, but powerful, gestures help establish the blues idiom from the very first measure.
• Incorporate the music of other cultures. While the blues is a fertile musical language, it’s important to not stop your journey there. Whether that means delving into the music of Africa, Brazil, the Caribbean, or elsewhere, it’s important to keep listening and trying new things, even if they may not come as easily as the blues.