Pentatonic Scale

The pentatonic scale is five notes selected from a seven-note major or minor scale, with the two most harmonically tense notes removed. The result is a scale that sounds good over almost anything. It's the first scale most guitarists learn, and for many players it remains the primary vehicle for improvisation across blues, rock, country, and jazz. Its apparent simplicity hides real depth — McCoy Tyner built an entire harmonic language from pentatonic superimposition.

Major Pentatonic

Take the major scale and remove the 4th and 7th degrees — the two notes that form the tritone and create the most harmonic tension:

Major scale:   C  D  E  F  G  A  B  C
               1  2  3  4  5  6  7
Remove 4, 7:   C  D  E     G  A

C major pentatonic: C D E G A
Intervals: W — W — m3 — W — m3
Formula: 1 — 2 — 3 — 5 — 6

Bright, open, unambiguously happy. Country licks, bluegrass melodies, gospel runs, folk songs — major pentatonic is ubiquitous. "Oh Susanna," "Amazing Grace," countless folk melodies worldwide are built on it. Notably, the major pentatonic is also the foundation of many non-Western musical traditions, including Chinese traditional music and Korean folk music.

Major Pentatonic in Common Keys

Key	Pentatonic Notes
C	C — D — E — G — A
G	G — A — B — D — E
D	D — E — F# — A — B
A	A — B — C# — E — F#
E	E — F# — G# — B — C#
F	F — G — A — C — D
B♭	B♭ — C — D — F — G

Minor Pentatonic

Take the natural minor scale and remove the 2nd and 6th degrees:

Natural minor: A  B  C  D  E  F  G  A
               1  2  ♭3  4  5  ♭6  ♭7
Remove 2, ♭6:  A     C  D  E     G

A minor pentatonic: A C D E G
Intervals: m3 — W — W — m3 — W
Formula: 1 — ♭3 — 4 — 5 — ♭7

Dark, gritty, immediately "rock" or "blues." The opening riff of "Smoke on the Water," most Led Zeppelin solos, the vocabulary of Eric Clapton, Jimi Hendrix, and SRV — minor pentatonic is the language of electric guitar improvisation. It works over minor chords and dominant seventh chords equally well, which is why it's so versatile in blues contexts where the chords are major or dominant but the feel is minor.

The Relative Relationship

C major pentatonic:  C D E G A
A minor pentatonic:  A C D E G   ← same notes, different root

They are the same five notes arranged starting from different roots.
This mirrors the relative major/minor relationship (C major ↔ A natural minor).

In practice: which one you're playing depends on context.
  Over C chord → C major pentatonic sounds "right" (bright, resolved)
  Over Am chord → A minor pentatonic sounds "right" (dark, settled)
  Over G7 chord → either works, creating different moods

Pentatonic Superimposition (Jazz Application)

Playing a pentatonic scale from an unexpected root over a chord to generate interesting extensions:

Chord	Play this pentatonic	Notes generated	Sound
Cmaj7	D major pentatonic (D E F# A B)	9, 3, #11, 6, 7	Rich Lydian extensions
G7	A minor pentatonic (A C D E G)	9, 11, 5, 13, ♭7	Full, modal sound
Dm7	F major pentatonic (F G A C D)	♭3, 4, 5, ♭7, 1	Classic minor
G7alt	A♭ major pentatonic (A♭ B♭ C E♭ F)	♭9, #9, 11, ♭13, ♭7	All alterations — modern jazz

McCoy Tyner's approach — playing Am pentatonic over major chords in quartal voicings — defined the post-bop piano sound. John Coltrane built his "sheets of sound" partly from cascading pentatonic runs through rapid chord changes.

Adding the Blue Note

Minor pentatonic + ♭5 = blues scale

A minor pentatonic: A  C  D  E  G
A blues scale:      A  C  D  E♭ E  G
                             ↑
                        blue note (♭5 / #4)

The ♭5 is a passing tone between 4 (D) and 5 (E).
Bend D toward E♭, or slide from E♭ to E.
Don't sustain on it — use it as a colour note.

References

• Levine — The Jazz Theory Book
• Berliner — Thinking in Jazz
• musictheory.net ↗