Abm7b5 guitar chord
Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top.
- Tap a note to hear it
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- Fingers, notes or intervals
- Play the chord
About Abm7b5 — shell voicings
Abm7b5 is Ab, Cb, D and Gb — Abm7 with the fifth lowered a semitone.
It sounds hollow, and unmistakably going somewhere. Almost always the first chord of a minor ii–V–i, so it walks straight into an altered dominant.
Abm7b5 notes and formula
| Ab | Cb | D | Gb |
|---|---|---|---|
| 1 | ♭3 | ♭5 | ♭7 |
Pre-dominant — the ii of a minor key.
Also written Abø, Abø7, Abm7-5, Abm7(b5) or Ab half diminished. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play Abm7b5
Root, third and seventh. The third and seventh, the guide tones, are what make the chord major, minor or dominant, so the fifth can go: it says nothing the symbol needs.
Three notes means a spare string, which is the real point. Put a tension on it.
Abm7b5 has 4 of them, on strings 6-4-3-2, strings 5-3-2-1 and the bottom four strings, from the 2nd fret up to the 10th — all in one inversion, so the bass note never moves. The one to learn first is the Ab shape at the 2nd fret.
Start with xx0102 — no barre and 2 open strings. 1 of the 8 shapes here sits in open position. 3 of the 8 need a barre. Together they cover the neck from the 1st fret to the 14th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| xx0102 | open position | Ebb, 2nd inversion | Gb | 2 open strings |
| 4x443x | 3rd fret | Ab, root position | D | barred |
| 4xx432 | 2nd fret | Ab, root position | Gb | all fretted |
| 456474 | 4th fret | Ab, root position | Ab | barred |
| xx6777 | 6th fret | Ab, root position | Cb | barred |
| x-11-9-11-9-10 | 9th fret | Ab, root position | D | all fretted |
| x-11-12-11-12-x | 11th fret | Ab, root position | Cb | all fretted |
| x-x-12-13-12-14 | 12th fret | Ebb, 2nd inversion | Gb | all fretted |
The same notes rebuilt from scratch give 14 drop 2, 10 drop 3 and 6 open string voicings, each on its own page.
Tensions. A shell of Abm7b5, root, third and seventh, leaves a string free, and the tones that belong over it are the 11 (Db) and the b13 (Fb).
How to use Abm7b5
Abm7b5 is the ii of Gb minor, which is where it is nearly always found: half-diminished, then an altered dominant, then the minor tonic.
In which keys. Every note of Abm7b5 belongs to F# minor (the ii°, the supertonic) and A major (the vii°, the leading tone).
What to play over Abm7b5
Every note of Abm7b5 is in Ab blues, Ab locrian, Ab altered and Ab half-whole diminished.
Chords near Abm7b5
Change one note of Abm7b5 and you have Abdim (drop the flat seventh), Abdim7 (the flat seventh becomes a sixth), Abm7 (the flat fifth becomes a fifth), AbmMaj7b5 (the flat seventh becomes a major seventh) or Ab7b5 (the minor third becomes a major third).
Abm7b5 is a diminished chord — root, minor third, flat fifth. Diminished and half-diminished chords on every root.
On Abm7b5’s sound and use this page follows Mark Levine, The Jazz Theory Book (Sher Music, 1995). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.