Diminished

Half-diminished ninth chords

A half-diminished (m7b5) chord with the natural 9th added: R, b3, b5, b7, 9 (C-Eb-Gb-Bb-D). The natural 9 sits a major 9th above the root and brightens the otherwise dark half-diminished sound, softening the tension of the ii-half-diminished in a minor key.

In every key

The same shape, moved. The symbols below are spelled the way the app spells them, which is the spelling the chord's own scale asks for rather than whichever accidental is easier to type.

  • Cm9b5
  • Dbm9b5
  • Dm9b5
  • Ebm9b5
  • Em9b5
  • Fm9b5
  • F#m9b5
  • Gm9b5
  • Abm9b5
  • Am9b5
  • Bbm9b5
  • Bm9b5

Voicings

Written in C, because that is the key the encyclopedia authors them in; every one transposes unchanged.

Root Position

C · Eb · Gb · Bb · D

advanced

LH C-Eb-Gb, RH Bb-D. The added D (9th) is what lifts it above a plain m7b5.

Rootless(b3-b5-b7-9)

Eb · Gb · Bb · D

advanced

Right hand 1-2-3-5 on Eb-Gb-Bb-D — an Eb-minor-major7 shape. Let the bass cover C.

Where it turns up

The ii-half-diminished-7 in a minor ii-V-i, enriched with the 9th for a more modern, less harsh half-diminished color. Common in the comping of Bill Evans, Kenny Barron, and Mulgrew Miller on minor turnarounds.

Commonly swapped with

  • Upper Eb-Gb-Bb-D reads as an Eb-minor-major color over C
  • Resolves to a minor V (e.g. F7alt) then to Fm