Guitar Scales for Blues - A Beginner’s Guide

Guitar scales for Blues is one of the most sought after topics to learn for guitar students. Blues music originated from African American musical traditions in the late 19th and early 20th centuries. It is deeply rooted in emotion, storytelling, and raw expression. The Blues scales on the guitar need to deliver a distinct sound and structure to deliver that ‘bluesy’ feel.

In this article, as we explore guitar scales for Blues, let’s break the topic part by part for a more profound understanding.

What is Blues Scale? 

Blues - as the name suggests, is all about deep emotion. It expresses feelings of longing, sorrow, struggle, hope, and resilience. And guitar scales that help to bring out melancholy, a sense of feeling low and a tug at the heart strings - all in the most effective manner are the Blue guitar scale.

Blues have simple lyrics but tell powerful, relatable stories. The way notes are played—bending, sliding, and vibrato—adds soulfulness and expressiveness. Even a simple melody can sound deeply emotional when played with a bluesy feel.

In these songs, sometimes there is a conversation between the vocal delivery of the artist and the guitar chords. And it is one of the most engaging and impactful music that has enthralled generations of listeners.

Over the years, various artists, such as B. B. King, Robert Johnson, Chuck Berry, John Meyer, and many more, have repeatedly created benchmarks through their unique blues scale techniques. This has led to a vast repertoire of techniques that collectively come under guitar scales for blues.

Blues guitar scales involve expressive scales, bends, slides, and phrasing to create the signature bluesy sound. While many scales can be used in blues, some are fundamental to getting that raw, emotional feel.

Let’s dive into the key Blues Guitar Scales and how to use them.

The Blues Scale – The Signature Sound

The blues scale is derived from the minor pentatonic scale, with an extra note called the "blue note" (♭5). This note adds a signature bluesy tension to the scale.

This blue note creates dissonance and tension, giving blues its signature raw and expressive sound.

Blues Scale Formula:
1 - ♭3 - 4 - ♭5 - 5 - ♭7 - 1

For example, the A Blues Scale consists of the notes:
A - C - D - D# (♭5) - E - G - A

The blue note is a flattened 5th (♭5) or sometimes a flattened 3rd (♭3) or 7th (♭7). It adds tension and a sense of "sadness" or "grit" to melodies.

In the above example - the D# (♭5) is the blue note. This note is often bent, slid into, or played subtly to emphasize its tension. It adds a slightly out-of-place, "crying" sound that defines the blues.

What is the ‘Out-of-key Blue Note’?

Before we go further into understanding the variations of Blues scales, let’s get a quick recap of the Minor Pentatonic Scale.

While the major scales are for bright and happy notes, the minor scales are used to evoke deep emotions of sorrow or ‘pensiveness’. Let’s see how this happens.

A minor scale is different from a major scale because of the third note being lowered by a half step.

Major Scale Example (C Major):
C - D - E - F - G - A - B - C

Here the third note (E) is a major third above C. This creates a bright, happy, and open sound. When we play the Major Chords C, G, E - the chords naturally vibrate with each other due to harmonic overtones (notes above the main or fundamental note - in this case G and E for C). 

When is comes to E♭ for the main tone C, it is not a strong harmonic overtone. Hence, this makes the resonance weaker leading to a darker, sombre and more emotional sound.

Minor Scale Example (C Minor):
C - D - E♭ - F - G - A♭ - B♭ - C

H2 Variations of Blues Notes

So far, we have learned that Blue notes don’t have a fixed pitch—they are often bent, slurred, or played microtonal to create expressiveness.

The three most common blue notes are -

Flat 3rd (♭3) 

This is the Classic "Bluesy" Minor Sound that occurs in both major and minor blues scales. It gives a melancholic, soulful feel. It often slides between minor (♭3) and major (3) for expressive tension.
Example:

• In C: E♭ (instead of E)
• In A: C (instead of C#)

The best example of Flat 3rd is - B.B. King's "The Thrill is Gone" 

This is one of the most emotionally powerful blues songs. It is noteworthy how B.B. King uses precise string bends to make his guitar "sing" like a human voice.

Bends refer to a guitar technique where you push (or pull) a string sideways across the fretboard to raise its pitch. Many of his bends are wide, expressive, and sustain beautifully, creating an aching, "crying" sound.

The other prominent element that imparts soulful expressions in this song is vibrato. Let’s see how it plays out on a guitar - 

The vibrato technique used in this song is fast, controlled, and wider than normal blues vibrato.

Instead of using the wrist, B.B. King often used his finger to shake the note, creating a unique "fluttering" effect.

Flat 5th (♭5) 

This note is also known as "The Devil’s Note" or Tritone. It is also called Augmented 4th (♯4) when moving up and Diminished 5th (♭5) when moving down. It makes the note sound tense and unstable. Used in blues, rock, and jazz to create a dark, unresolved sound. 

This note earns the name of "Diabolus in Musica" (The Devil's Note) because of its dissonant, unstable sound. This interval is central to blues, rock, metal, jazz, and even classical music.

Example:

• In C: G♭ (F# instead of G)
• In A: D♯/E♭ (instead of E)

In the song ‘Purple Haze’, Jimi Hendrix embraced dissonance and used the tritone as a key part of his signature sound.

The main riff of "Purple Haze" revolves around a Tritone interval between E and B♭ (A#). This interval creates a dark, tension-filled, and aggressive feel—perfect for psychedelic blues-rock.

The tritone resists resolution, meaning your ear expects it to resolve but it doesn’t. This creates tension and gives the song an unhinged, hypnotic quality. 

Flat 7th (♭7) 

This is the "Bluesy" Dominant Sound that gives the dominant 7th feel in blues progressions. It adds a laid-back, raw, and cool blues feel.

Example:

• In C: B♭ (instead of B)
• In A: G (instead of G#)

This note has been used in Robert Johnson’s "Sweet Home Chicago"

Another key characteristic of Blues music is storytelling. Listen to Robert Johnson’s "Sweet Home Chicago". Its lyrics follow a classic blues call-and-response pattern. 

On the guitar, it follows the classic 12-bar blues progression, creating a familiar, grooving rhythm.

The structure revolves around three primary chords (I – IV – V):

• I (Tonic) = E7
• IV (Subdominant) = A7
• V (Dominant) = B7

Johnson uses the E Blues Scale (E–G–A–Bb–B–D), especially for bending notes to add tension. He slides it between notes for smooth transitions and repetitive phrases that "talk back" to his voice.

Types of Blues Scale

In blues music, scales can have six (hexatonic), seven (heptatonic), or nine (nonatonic) notes. Each variation adds or removes notes to influence the feel, mood, and melodic possibilities.

Also read - Guitar Scales for Beginners

Let’s briefly go through all the Blues scale types - 

Hexatonic Blues Scale (6-Note Scale)

This is a six-note scale formed by adding a "blue note" (♭5) to the minor pentatonic scale. It uses the formula - 1 - ♭3 - 4 - ♭5 - 5 - ♭7.

Example in A Minor Blues:
A - C - D - E♭ - E - G

It sounds raw, gritty, and expressive. It is the core of blues and rock guitar playing. This type works well over dominant 7th chords (A7, D7, E7 in a 12-bar blues). It is mostly used in blues, rock, metal, funk, and country guitar solos.

Heptatonic Blues Scale (7-Note Scale)

It is a seven-note scale that adds a major 2nd (2) or major 6th (6) to the hexatonic blues scale. This blend of major and minor tones creates a jazzier, more melodic feel. It uses the formula - 1 - 2 - ♭3 - 4 - ♭5 - 5 - ♭7. 

Example in A Minor Blues:
A - B - C - D - E♭ - E - G

This type of Blues scale makes the songs smoother and more melodic than the traditional blues scale. The major 2nd (B in A minor) gives a jazzier sound, used in bebop and fusion. This type is mostly found in modern blues, jazz fusion, and progressive rock guitar solos.

Nonatonic Blues Scale (9-Note Scale)

This is a nine-note scale that adds chromatic passing tones to make solos fluid and expressive. It uses the formula -  1 - 2 - ♭3 - 3 - 4 - ♭5 - 5 - 6 - ♭7

Example in A Minor Blues:
A - B - C - C# - D - E♭ - E - F# - G

The sound is chromatic, jazzy, and expressive – perfect for bebop and jazz-fusion. It adds extra passing notes for smooth transitions between tones. This scale is used by Wes Montgomery, Charlie Parker (in bluesy jazz solos), and John Scofield.

Concluding Guitar Scales for Blues

Our ears are naturally tuned to recognize sounds that feel stable and pleasant. Major chords have a strong and clear connection between their notes, making them sound bright and happy. This is because of the way the overtones, or extra vibrations, naturally blend together.

On the other hand, minor chords do not have the same direct connection. Their notes create a different kind of vibration, which the brain interprets as something unresolved or emotional. This is why minor chords often sound sad, mysterious, or dramatic. In blues music, this feeling is very important. The slightly "off" or unresolved sound of minor chords and blue notes gives blues its emotional depth. This "bluesy" feel is something that both listeners and guitarists love because it adds soul and expression to the music.

If you are a fan of bluesy music and would like to play your favorite tracks on guitar, then you can explore online guitar classes.