Guitar Theory
Harmonic Minor vs Natural Minor
Harmonic minor and natural minor differ by exactly one note: the 7th degree. In harmonic minor it is raised by a half step. That one change produces one of the most dramatic and instantly recognizable sounds in guitar, used everywhere from classical music to metal to flamenco.
Natural minor: the flat 7th
The natural minor scale has a flat 7th. In A natural minor, the 7th degree is G natural, two semitones below the root (A). The scale resolves back to the root from that G, but the resolution is soft. There is no strong pull.
A natural minor
Harmonic minor: the raised 7th
Harmonic minor raises the 7th by one semitone. In A harmonic minor, that changes G natural to G#. Now the 7th sits just one half step below the root. That tiny distance creates a strong gravitational pull back to the root. Classical theory calls this a leading tone because it leads the ear home.
A harmonic minor
The amber note (G#) is the raised 7th. One semitone below the root. This creates a powerful pull back to A.
The augmented 2nd: the exotic interval
Raising the 7th creates a side effect: a gap of three semitones between the 6th and the 7th (F to G# in A harmonic minor). That is an augmented 2nd, an interval that does not appear in the major scale or natural minor. It sounds Middle Eastern, Spanish, and dramatic. It is the interval responsible for harmonic minor's distinctive, exotic character.
When you run a scale passage through that gap, the jump from F to G# is audibly unusual. It is too wide to be a normal scale step but too narrow to be a skip. That ambiguity is exactly what makes harmonic minor sound so striking.
Why it is called harmonic minor
The name comes from harmony, not melody. Classical composers raised the 7th specifically to strengthen the V chord. In A natural minor, the V chord is Em (E G B). With the raised 7th, it becomes E major (E G# B). A major V chord in a minor key creates a much stronger resolution back to the i chord than a minor v chord does. The scale was modified to support that harmonic move.
This is why harmonic minor is so common in diatonic chord progressions that end on the V chord resolving to i. The V major to i minor cadence is one of the most powerful movements in music.
How guitarists use harmonic minor
Built arpeggios and scale runs from harmonic minor for classical-influenced metal solos. Crazy Train and Mr. Crowley are built around it.
Yngwie Malmsteen
Made harmonic minor his primary language. Near-constant use of the augmented 2nd, neoclassical runs, and V-i cadences borrowed from Baroque composition.
Used the raised 7th as a leading tone over slow blues, giving minor key blues a more dramatic, classical quality.
Reaches for harmonic minor on Metallica solos that need maximum darkness and tension, particularly on tracks with Spanish or Eastern influences.
When to use each
Use natural minor for darker, heavier passages where you want the flat 7th's weight. Natural minor is the default for most rock and metal. Use harmonic minor when you want dramatic resolution, classical tension, or that exotic augmented 2nd jump. It fits especially well over a V chord in a minor key and in passages where you want the leading tone pull back to the root.
Compared to Dorian, which brightens minor by raising the 6th, harmonic minor raises the 7th for a completely different effect. Dorian sounds sophisticated and hopeful. Harmonic minor sounds dramatic and tense.
Compare both scales on the fretboard
Load A natural minor and A harmonic minor in the Scale Mapper. The single note that changes is immediately visible across every position on the neck.
Open Scale Mapper →