Skip to content

Half Diminished Chords on Piano

The half-diminished chord (m7♭5) is a diminished triad with a minor seventh — darker than a minor 7th but softer than a fully diminished 7th. It is essential for minor-key jazz harmony, serving as the ii chord in minor-key ii–V–i progressions.

Formula: Root – Minor 3rd – Diminished 5th – Minor 7th
Intervals: 3 + 3 + 4 semitones
Scale degrees: 1–♭3–♭5–♭7
Sound: Dark, moody, tense, yearning
Symbol: m7♭5, ø, ø7 (Cm7♭5, Cø)

The minor-key ii–V–i: Half-diminished chords are most commonly the ii chord in minor keys. For example, Dm7♭5 → G7 → Cm is a standard jazz minor cadence. Every jazz musician must know half-diminished chords in all keys — they appear in nearly every minor-key standard.

Half Diminished Chord in All 18 Keys