Ab Half-Diminished Seventh (Minor 7♭5)

Chord Tones: Ab Half-Diminished Seventh (Minor 7♭5)

Symbol: ø7, m7♭5 — Formula: 1-♭3-♭5-♭7

DegreeNoteFrequency (A=440, Equal)
1 Ab 415.305 Hz
♭3 B 493.883 Hz
♭5 D 293.665 Hz
♭7 Gb 369.994 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolAbø7
All Common Symbolsø7, m7♭5
Interval Formula1-♭3-♭5-♭7
Harmonic Categorydissonant

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

InversionNotes (low to high)Bass NoteSlash Notation
Root Position Ab B D Gb Ab Ab Half-Diminished Seventh (Minor 7♭5)
First Inversion B D Gb Ab B Ab Half-Diminished Seventh (Minor 7♭5)/B
Second Inversion D Gb Ab B D Ab Half-Diminished Seventh (Minor 7♭5)/D
Third Inversion Gb Ab B D Gb Ab Half-Diminished Seventh (Minor 7♭5)/Gb

Harmonic Function

The Ab half diminished chord commonly functions as the submediant (♭VI) in C minor or subdominant in E♭ major. Its harmonic role varies by key — in major keys it provides stable harmonic grounding.

The half-diminished chord (minor seven flat five) combines a diminished triad with a minor seventh. It is the ii chord in minor keys and an essential sound in jazz and classical harmony.

Common Progressions

The Ab Half-Diminished Seventh (Minor 7♭5) frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

Songs Featuring the Half-Diminished Seventh (Minor 7♭5)

Well-known songs where the Ab Half-Diminished Seventh (Minor 7♭5) — or this chord type — plays a prominent role:

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

NoteEqual Temp.PythagoreanJust Intonation
Ab 415.305 Hz 417.657 Hz 418.601 Hz
B 493.883 Hz 495.000 Hz 490.548 Hz
D 293.665 Hz 293.332 Hz 294.329 Hz
Gb 369.994 Hz 371.251 Hz 367.911 Hz

Scales Containing the Ab Half-Diminished Seventh (Minor 7♭5)

These scales include the Ab Half-Diminished Seventh (Minor 7♭5) as a diatonic or characteristic chord: