Half-Diminished 7 on Piano
What do half-diminished 7 sound like?
Melancholy suspended in mid-air — darker than m7, softer than diminished. The half-diminished chord aches rather than alarms.
How are they built?
A diminished triad plus a MINOR 7th: root, ♭3, ♭5, ♭7. Also written m7♭5 — a minor 7 whose 5th collapsed a half step.
What is their job in a progression?
The ii chord of minor keys: iiø7–V7–im is THE minor cadence. Its ♭5 already points at the V's 9th, so the resolution feels inevitable.
Where you'll hear them
"Autumn Leaves" bar one, "Stairway to Heaven"'s descending line, bossa nova's saddest turns — the gateway chord to sounding like you know jazz.
The beginner mistake
Mixing it up with the fully diminished 7. Half-diminished keeps the MINOR 7th (one half step higher than dim7's ♭♭7) — that single note is the difference between ache and panic.
Fingering logic
The narrow ♭3-♭5 middle packs fingers 2-3 close together: 1-2-3-5 with a consciously relaxed middle of the hand stops the compressed shape from tensing up.
Half-Diminished 7 in all 12 keys
Neighboring families
Chord Rush drills half-diminished 7 in every key until recognition is instant — reading time becomes playing time.
- ⚡Speed
- ◎Accuracy
- ♪Recognition