The Double Harmonic Family

The double harmonic and its rotations, the Hungarian minor among them: two lowered degrees from the major scale, one from the harmonic major, and its own mirror image around the root.

The seven modes, by rotation

Each mode starts the family on the next degree up. Names are the source’s; degrees, neighbour counts and mirrors are worked out here.
Mode Name, as printed Degrees One degree away Reflected
Mode 1 Double harmonic 1 b2 3 4 5 b6 7 3 itself
Mode 2 Lydian #2 #6 1 #2 3 #4 5 #6 7 2 Locrian bb3 bb7
Mode 3 Phrygian bb7 b4 (or Altered Diminished #5) 1 b2 b3 b4 5 b6 bb7 2 Ionian #5 #2
Mode 4 Hungarian minor or Lydian Diminished b6 1 2 b3 #4 5 b6 7 3 Locrian natural 6 natural 3
Mode 5 Locrian natural 6 natural 3 or Mixolydian b5 b2 1 b2 3 4 b5 6 b7 3 Hungarian minor
Mode 6 Ionian #5 #2 1 #2 3 4 #5 6 7 3 Phrygian bb7 b4
Mode 7 Locrian bb3 bb7 1 b2 bb3 4 b5 b6 bb7 2 Lydian #2 #6

Names as printed in Mode (music), “Other heptatonic scales” (Wikipedia, read 2026-09-24).

Interval content

How many of the twenty-one pairs of notes in the family lie each distance apart, the shorter way round: the interval vector <4 2 4 5 4 2>.
Semitones apart 1 2 3 4 5 6
Pairs 4 2 4 5 4 2

Mirror and symmetry

Reflected around its root, every mode of the double harmonic family lands on another mode of the same family, and Double harmonic lands on itself. No shift short of the octave maps the family onto itself: seven notes cannot divide twelve evenly.

One degree away

Every altered degree that carries a mode of this family onto a mode the atlas declares: eighteen in all, reaching harmonic minor, harmonic major and Neapolitan minor.
From Alter Lands on Family
Double harmonic raise the 2nd (b2 to 2) Harmonic major Harmonic major
Double harmonic lower the 3rd (3 to b3) Neapolitan Minor Neapolitan minor
Double harmonic lower the 7th (7 to b7) Phrygian Dominant Harmonic minor
Lydian #2 #6 lower the 2nd (#2 to 2) Lydian #6 Neapolitan minor
Lydian #2 #6 lower the 6th (#6 to 6) Lydian #2 Harmonic minor
Phrygian bb7 b4 lower the 5th (5 to b5) Altered Diminished Harmonic minor
Phrygian bb7 b4 raise the 7th (bb7 to b7) Phrygian b4 Harmonic major
Hungarian minor lower the 4th (#4 to 4) Harmonic minor Harmonic minor
Hungarian minor raise the 6th (b6 to 6) Lydian b3 Harmonic major
Hungarian minor lower the 7th (7 to b7) Romani Minor Neapolitan minor
Locrian natural 6 natural 3 lower the 3rd (3 to b3) Locrian #6 Harmonic minor
Locrian natural 6 natural 3 raise the 5th (b5 to 5) Mixolydian b2 Harmonic major
Locrian natural 6 natural 3 lower the 6th (6 to b6) Locrian Dominant Neapolitan minor
Ionian #5 #2 lower the 2nd (#2 to 2) Ionian #5 Harmonic minor
Ionian #5 #2 raise the 4th (4 to #4) Lydian Augmented #2 Harmonic major
Ionian #5 #2 lower the 5th (#5 to 5) Ionian/Major #2 Neapolitan minor
Locrian bb3 bb7 raise the 3rd (bb3 to b3) Locrian bb7 Harmonic major
Locrian bb3 bb7 lower the 4th (4 to b4) Ultralocrian/Altered Diminished bb3 Neapolitan minor

What the sources say about it

Every relation a source states that involves this family, tested against the atlas.
The claim In the atlas The source’s words
Ionian (diatonic, mode 1): lower the 2nd and lower the 6th, and it is Double harmonic (double harmonic, mode 1). Borne out in two altered degrees, stopping at Harmonic major (harmonic major, mode 1) on the way. lowering both the second and sixth of the Ionian mode by a semitone. — Double harmonic scale, “Details” (Wikipedia, read 2026-09-24)
Harmonic minor (harmonic minor, mode 1): lower the 2nd and raise the 3rd, and it is Double harmonic (double harmonic, mode 1). Borne out in two altered degrees, stopping at Neapolitan Minor (Neapolitan minor, mode 1) and Harmonic major (harmonic major, mode 1) on the way. lowering the second note and raising the third note of the harmonic minor scale by one semitone. — Double harmonic scale, “Details” (Wikipedia, read 2026-09-24)
Phrygian Dominant (harmonic minor, mode 5): raise the 7th, and it is Double harmonic (double harmonic, mode 1). Borne out: the two are one altered degree apart. raising the seventh of the Phrygian dominant scale (a mode of the harmonic minor scale) by a semitone. — Double harmonic scale, “Details” (Wikipedia, read 2026-09-24)
Neapolitan Minor (Neapolitan minor, mode 1): raise the 3rd, and it is Double harmonic (double harmonic, mode 1). Borne out: the two are one altered degree apart. raising the third of the neapolitan minor scale by a semitone. — Double harmonic scale, “Details” (Wikipedia, read 2026-09-24)
Harmonic major (harmonic major, mode 1): lower the 2nd, and it is Double harmonic (double harmonic, mode 1). Borne out: the two are one altered degree apart. lowering the second note of the harmonic major scale by a semitone. — Double harmonic scale, “Details” (Wikipedia, read 2026-09-24)
Double harmonic (double harmonic, mode 1) reflected around its root is itself. Borne out: the reflection lands there. The double harmonic major is its own reflection around the root, itself being the palindromic mode. — Double harmonic scale, “Symmetry and balance” (Wikipedia, read 2026-09-24)

The family itself is read from Double harmonic scale, “Details” (Wikipedia, read 2026-09-24): lowering the second note of the harmonic major scale by a semitone..

Two lowered degrees

The double harmonic family starts from the double harmonic, 1 b2 3 4 5 b6 7: the major scale with its second and sixth both lowered. Its rotations include Lydian #2 #6, the Hungarian minor, 1 2 b3 #4 5 b6 7, and Locrian bb3 bb7, each named as the source prints it.

Two alterations, one stop

Lowering both of those degrees at once is two alterations, so the double harmonic is not a neighbour of Ionian. Take them one at a time and the route passes through a declared set: lower the sixth first and Ionian becomes the harmonic major; lower the harmonic major’s second and it becomes the double harmonic. Lowering the second first leads out of the atlas, so that order has no stop here. From the harmonic minor the same thing happens twice over: lower its second and raise its third, in either order, and the route stops at the Neapolitan minor one way and at the harmonic major the other.

Its nearest neighbours

One altered degree connects its modes to the harmonic minor, harmonic major and Neapolitan minor families, and to nothing else. Its modes have few neighbours: none has more than three, and three have only two.

Symmetric around its root

Reflected around its root, the double harmonic is itself: the steps above its root, read upward, are the steps below it read downward. The family’s other modes pair off under the same reflection, Lydian #2 #6 with Locrian bb3 bb7 among them.