Minor Scales

There are three forms of the minor scale: natural minor (Aeolian), harmonic minor (raised 7th), and melodic minor (raised 6th and 7th ascending). Each serves a different harmonic purpose and sounds different. Most minor key music uses all three in combination, and understanding which form fits which context is the core of minor key harmony. Jazz melodic minor deserves its own section — it's a fundamentally different beast from its classical namesake.

Natural Minor (Aeolian Mode)

A natural minor: A B C D E F G A
Formula: W — H — W — W — H — W — W
Degrees: 1   2  ♭3  4   5  ♭6  ♭7

The natural minor is just the major scale starting from its 6th degree. A natural minor uses the same notes as C major. Its V chord is a minor chord (Em7 in A minor) — it has less pull toward the tonic than a dominant seventh. This is the default minor sound: dark but not dramatic, commonly used in rock, folk, and modal jazz.

Diatonic Chords of Natural Minor

Degree	Chord (A minor)	Quality	Function
i	Am7	Minor 7th	Tonic
ii°	Bm7♭5	Half-diminished	Pre-dominant
♭III	Cmaj7	Major 7th	Relative major's tonic
iv	Dm7	Minor 7th	Subdominant
v	Em7	Minor 7th	Weak dominant (no leading tone)
♭VI	Fmaj7	Major 7th	Subtonic — often strong
♭VII	G7	Dominant 7th	Subtonic dominant — strong in rock

Harmonic Minor

A harmonic minor: A B C D E F G# A
Formula: W — H — W — W — H — A2 — H
Degrees: 1   2  ♭3  4   5  ♭6   7

A2 = augmented second (3 semitones) between ♭6 and 7

Raising the 7th creates G# — the leading tone — which pulls strongly up to the tonic A. It also turns the V chord from Em7 (minor) to E7 (dominant seventh), giving the classic tonal cadence in minor key music. The augmented second between F and G# (or ♭6 to maj7) is the distinctive sound — it gives harmonic minor its exotic, dramatic quality.

Compared to natural minor	Result
V chord: Em7 → E7	Dominant function restored — strong pull to tonic
Leading tone: G → G#	Half step below tonic — the strongest possible approach
♭6 to 7: F to G#	Augmented second — the characteristic "eastern" sound
vii° chord: becomes fully diminished	Gdim7 — another strong dominant function chord

Melodic Minor (Classical)

A melodic minor:
  Ascending: A B C D E F# G# A   (raise ♭6 and ♭7)
  Descending: A G F E D C B A    (same as natural minor)

The classical melodic minor resolves the awkward augmented second of harmonic minor by also raising the 6th. Ascending, the scale sounds smooth and singable. Descending, the raised notes aren't needed (no upward leading tone required), so it reverts to natural minor. This ascending/descending asymmetry is a classical rule that jazz ignores entirely.

Melodic Minor (Jazz Form)

A melodic minor (jazz): A B C D E F# G# A  (same both directions)
Formula: W — H — W — W — W — W — H
Degrees: 1   2  ♭3  4   5   6   7

Jazz treats the melodic minor as a fully independent scale with seven distinct modes, each with its own harmonic character. The jazz melodic minor — also called the "jazz minor" — is a major scale with a lowered third. Its modes produce some of the most important sounds in jazz harmony:

Mode of melodic minor	Common name	Used over
1st (I)	Jazz melodic minor	Im(maj7), ImMaj9
2nd	Dorian ♭2 (Phrygian ♮6)	sus♭9 chords
3rd	Lydian Augmented	maj7#5 chords
4th	Lydian Dominant	7#11 chords (tritone sub dominant)
5th	Mixolydian ♭6	7♭13 chords
6th	Locrian ♮2 (Half-diminished)	m7♭5 chords
7th	Altered scale (Super Locrian)	7alt chords — all altered extensions

Choosing Which Minor Scale

Situation	Scale choice	Why
Minor tonic chord (Im7) in jazz	Dorian or jazz melodic minor	Dorian (raised 6th) is brighter; melodic minor gives major 7th sound
Minor tonic in rock/metal	Natural minor (Aeolian)	Darker, raw quality; ♭7 chord is strong in rock
V7 in a minor key cadence	Harmonic minor or altered scale	Need the leading tone (raised 7th) for strong cadence
Running scalar passages in classical	Melodic minor ascending, natural descending	Smooth voice leading in both directions
Exotic, dramatic quality	Harmonic minor	The augmented 2nd is the characteristic "eastern" sound
Fast runs in gypsy/flamenco style	Phrygian dominant or harmonic minor	The characteristic half-step approach from ♭2

References

Levine — The Jazz Theory Book
Aldwell & Schachter — Harmony and Voice Leading
musictheory.net — Minor Scales ↗