Half-Diminished (Minor 7 Flat 5)
Abø7 is a diminished chord rooted on Ab. It creates intense tension and instability, functioning as a leading tone chord or a passing chord in jazz harmony. The half-diminished (m7b5) is the most common form, serving as the ii chord in minor key ii-V-i progressions (Levine, The Jazz Theory Book).
28 voicings · diminished
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Melody (F#5) doubled an octave below (F#4) with chord tones in between
Left hand alternates between bass note and chord
Beat 1 & 3 — Ab3
Beat 2 & 4 — D, F#, B
Left hand alternates between bass note and chord
Beat 1 & 3 — Eb3
Beat 2 & 4 — D, F#, B
The half-diminished chord (also written as Abø7) functions as the ii chord in minor keys — it is to minor keys what the minor seventh is to major keys (Mulholland & Hojnacki, The Berklee Book of Jazz Harmony). Fully diminished seventh chords function as passing chords or dominant substitutions. Levine notes that the half-diminished is one of the most misunderstood chords in jazz — it needs to be voiced carefully to avoid harshness (The Jazz Piano Book).
Half-diminished chords pair with the Locrian mode or, more commonly, Locrian #2 (the sixth mode of melodic minor). Fully diminished chords use the whole-half diminished scale (Aebersold, Jazz Handbook).
Half-diminished chords typically resolve to a dominant seventh chord a fourth above (in minor ii-V-i). Fully diminished chords resolve up a half step (Levine, The Jazz Theory Book).
Minor ii-V-i
Abø7 as the ii chord in a minor key ii-V-i
Passing diminished
Connecting two diatonic chords a whole step apart
Turnaround
iii-VI-ii-V with Abø7 as the ii
Abø7 is a diminished chord built on Ab with a flattened fifth. In jazz, this chord most commonly appears as the ii chord in minor key progressions (Levine, The Jazz Theory Book).
Shell voicings work well: root, b3, b5, b7. Rootless voicings are also effective. Mantooth recommends practising minor ii-V-i progressions to build fluency with half-diminished voicings (Voicings for Jazz Keyboard).
The half-diminished chord is the starting point of the minor ii-V-i progression — learning to voice it smoothly is essential for playing in minor keys.
— Mantooth, Voicings for Jazz Keyboard
Locrian #2 (from melodic minor) is preferred over natural Locrian because the raised second avoids a minor ninth interval above the root.
— Levine, The Jazz Theory Book, pp. 56-58