The standard grips this chord is usually shown with.
Abaug9 is Ab, C, E, Gb and Bb — Ab7 with the fifth raised and the natural ninth added on top.
It sounds bright, tense and slightly unreal. Raising the fifth leaves no semitone in the lower half of the chord, which is where the whole-tone flavour comes from.

| Ab | C | E | Gb | Bb |
|---|---|---|---|---|
| 1 | 3 | ♯5 | ♭7 | 9 |
Altered dominant — dominant pull with a whole-tone colour.
Also written Ab9#5, Ab+9 or Ab9(#5). The same chord either way; which spelling you meet depends on who wrote the chart.
Abaug9 in root position puts Ab in the bass, which is the chord as it is spelled: the note it is named after underneath everything else.
4 of Abaug9’s 8 common shapes do this: 434350, 4x4556, x-11-10-11-11-0, x-11-10-11-11-12.
Start with xx4556 — no barre and low, at the 4th fret. 1 of the 8 shapes here sits in open position. 5 of the 8 need a barre. Together they cover the neck from the 1st fret to the 14th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| 212112 | 1st fret | Gb, 3rd inversion | Gb | barred |
| 434350 | open position | Ab, root position | E | 1 open string |
| 4x4556 | 4th fret | Ab, root position | Bb | all fretted |
| xx4556 | 4th fret | Gb, 3rd inversion | Bb | all fretted |
| 898998 | 8th fret | C, 1st inversion | C | barred |
| x-11-10-11-11-0 | 10th fret | Ab, root position | Bb | barred |
| x-11-10-11-11-12 | 10th fret | Ab, root position | E | barred |
| 14-13-14-13-13-14 | 13th fret | Gb, 3rd inversion | Gb | barred |
The same notes rebuilt from scratch give 5 shell, 13 rootless and 2 open string voicings, each on its own page.
Tensions. A shell of Abaug9, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (D).
Abaug9 is a dominant with its tension raised, so it still points at Db — harder than a plain seventh does, because the altered tones sit a semitone from where they are going.
Every note of Abaug9 is in Ab whole tone.
Change one note of Abaug9 and you have Abalt (the ninth becomes a flat ninth), Abaug7 (drop the ninth), Ab9 (the sharp fifth becomes a fifth) or Ab9b5 (the sharp fifth becomes a flat fifth).
Abaug9 is an altered chord — a dominant seventh with its fifth or ninth moved. Altered dominant chords on every root.
On Abaug9’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.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.