Aaug9 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
- Arrows change position
- Fingers, notes or intervals
- Play the chord
About Aaug9 — shell voicings
Aaug9 is A, C#, E#, G and B — A7 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.
Aaug9 notes and formula
| A | C# | E# | G | B |
|---|---|---|---|---|
| 1 | 3 | ♯5 | ♭7 | 9 |
Altered dominant — dominant pull with a whole-tone colour.
Also written A9#5, A+9 or A9(#5). The same chord either way; which spelling you meet depends on who wrote the chart.
How to play Aaug9
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.
Aaug9 has 8 of them, on the bottom four strings, the middle four strings, the top four strings, strings 5-3-2-1 and strings 6-4-3-2, from open position up to the 12th — all in one inversion, so the bass note never moves. The one to learn first is the A shape at the 4th fret, which is the easiest grip here.
3 of them sit on strings 5-3-2-1, so you can run the inversions up one set without changing strings — which is the whole reason to learn them as a family rather than as separate grips.
Start with x03423 — no barre and 1 open string. 2 of the 11 shapes here sit in open position. 4 of the 11 need a barre. Together they cover the neck from the 2nd fret to the 15th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| 323223 | 2nd fret | G, 3rd inversion | G | barred |
| x03423 | open position | A, root position | G | 1 open string |
| 543005 | open position | A, root position | A | 2 open strings |
| 54546x | 4th fret | A, root position | E# | all fretted |
| x05667 | 5th fret | A, root position | B | 1 open string |
| 5x5667 | 5th fret | A, root position | B | all fretted |
| xx5667 | 5th fret | G, 3rd inversion | B | all fretted |
| 9-10-9-10-10-9 | 9th fret | C#, 1st inversion | C# | barred |
| x-12-11-12-0-13 | 11th fret | A, root position | E# | 1 open string |
| x-12-11-12-12-13 | 11th fret | A, root position | E# | barred |
| 15-14-15-14-14-15 | 14th fret | G, 3rd inversion | G | barred |
The same notes rebuilt from scratch give 14 rootless and 2 open string voicings, each on its own page.
Tensions. A shell of Aaug9, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (D#).
How to use Aaug9
Aaug9 is a dominant with its tension raised, so it still points at D — harder than a plain seventh does, because the altered tones sit a semitone from where they are going.
Voice by voice, Aaug9 → D. 3 voices move by a semitone, and one note is common to both chords.
| In Aaug9 | Moves | In D |
|---|---|---|
| A, the root | stays where it is | A, the fifth |
| C#, the major third | rises a semitone | D, the root |
| E#, the sharp fifth | rises a semitone | F#, the major third |
| G, the flat seventh | falls a semitone | F#, the major third |
| B, the ninth | falls a whole tone | A, the fifth |
What to play over Aaug9
Every note of Aaug9 is in A whole tone.
Chords near Aaug9
Change one note of Aaug9 and you have Aalt (the ninth becomes a flat ninth), Aaug7 (drop the ninth), A9 (the sharp fifth becomes a fifth) or A9b5 (the sharp fifth becomes a flat fifth).
Aaug9 is an altered chord — a dominant seventh with its fifth or ninth moved. Altered dominant chords on every root.
On Aaug9’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.