1. The minor pentatonic — the foundation
The minor pentatonic is the single most-used scale in blues and rock. It has five notes per octave, spelled 1 · b3 · 4 · 5 · b7. In the key of A that is A, C, D, E, G.
Its appeal is that almost every note sounds good over a blues, so it is forgiving for beginners and endlessly expressive for pros. It works over both minor and dominant 7th blues progressions, which is why it is the default starting point for soloing. Build muscle memory with the box shapes in the A minor pentatonic on the fretboard.
2. The blues scale — add the blue note
Take the minor pentatonic and slip in one extra note — the flat 5th (b5) — and you have the six-note blues scale: 1 · b3 · 4 · b5 · 5 · b7. In A that is A, C, D, Eb, E, G.
That added b5 is the famous "blue note". It sits between the 4th and 5th and creates the aching, dissonant tension that defines the blues. It is a passing tone — you slide or bend through it on the way to the 5th rather than parking on it. Used sparingly it transforms straight pentatonic licks into genuine blues. Explore it on the fretboard with the A blues scale.
This page is about choosing a scale. For the fretboard side — which boxes the blues scale occupies and exactly where the b5 falls in each one — see blues scale shapes on the fretboard, and the five pentatonic shapes underneath it.
3. The major pentatonic — the sweet sound
The major pentatonic (1 · 2 · 3 · 5 · 6, so A B C# E F# in A) is brighter and happier. It is the sound of country blues, early rock and roll, and players like B.B. King and Chuck Berry. Over a dominant blues you can use it because the underlying chords are major-flavoured.
A handy shortcut: the major pentatonic of a key uses the same shape as the minor pentatonic a minor third lower. The A major pentatonic shape is the same as the F# minor pentatonic shape — so once you know your minor boxes, the major ones are already under your fingers. Try the A major pentatonic to hear the contrast.
4. Mixolydian — for the chord tones
A standard blues is built on dominant 7th chords, and the mode that matches a dominant 7th chord is Mixolydian (the major scale with a flat 7th: 1 · 2 · 3 · 4 · 5 · 6 · b7). Players reach for Mixolydian when they want to outline each chord clearly and land on chord tones rather than just wail on the pentatonic.
In practice, advanced blues players switch their target notes as the chords change, leaning into Mixolydian colour over each dominant chord. If you are new to modes, read the overview of the seven modes first to see where Mixolydian fits.
Blending the scales
The signature electric-blues sound comes from mixing the minor and major pentatonics over the same key. The b3 from the minor scale and the major 3rd from the major scale rub against each other, and sliding between them is the essence of blues phrasing. B.B. King, Eric Clapton, and Stevie Ray Vaughan all live in this overlap.
Bend into the blue note
Bend the 4th up toward the b5, or the b3 up toward the major 3rd, to get that vocal, crying quality.
Target chord tones
Land your phrases on the root, 3rd, or b7 of whichever chord is playing for a sound that follows the progression.
Leave space
The best blues lines breathe. Play a short phrase, then rest — the silence is part of the music.
Use the blue note as a passing tone
Slide through the b5 rather than holding it; its tension wants to resolve to the 4th or 5th.
Where the 12-bar blues comes in
These scales are usually played over a 12-bar blues — a I–IV–V progression using dominant 7th chords. In A that is A7, D7, and E7. One of the simplest ways to internalise the scales is to loop a 12-bar backing and solo with one scale at a time, then start combining them. For the chord side of the equation, see the beginner chord progressions guide, which covers the 12-bar blues in detail.
Related on String Warrior
Drill the shapes on your instrument, then connect them to the harmony.