A7#9 guitar chord
Playable, correctly spelled, and not how the chord is normally voiced. Right now this is the shapes that put a ninth, eleventh or thirteenth below the root.
- Tap a note to hear it
- Arrows change position
- Fingers, notes or intervals
- Play the chord
About A7#9 — uncommon voicings
A7#9 is A, C#, E, G and B# — A9 with the ninth raised a semitone.
It sounds gritty and contradictory. The minor third sounding over the major third; every guitarist knows it as the Hendrix chord.
Altered dominant — dominant function with a blues third on top.
A7#9 notes and formula
| A | C# | E | G | B# |
|---|---|---|---|---|
| 1 | 3 | 5 | ♭7 | ♯9 |
Also written A7(#9), A7+9 or A7♯9. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play A7#9
Five notes and four fingers, so something has to go. Keep C#, G and B# (they fix the quality). Let E and A go, in that order — a perfect fifth says nothing the root has not, and in a band the bass has the root.
Play A7#9 as a shell — root, third and seventh — and the spare string takes the #11 (D#), the b13 (F) or the 13 (F#).
All 9 common shapes as fret numbers, lowest string first. Hover or tap one to see it drawn.
- x32223, 2nd fret, B#, 9th in the bass, top note G, barred
- 5455xx, 4th fret, A, root position, top note B#, barred
- x45555, 4th fret, C#, 1st inversion, top note A, barred
- 575688, 5th fret, A, root position, top note B#, all fretted
- 575658, 5th fret, A, root position, top note B#, barred
- xx7688, 6th fret, A, root position, top note B#, all fretted
- x77688, 6th fret, E, 2nd inversion, top note B#, all fretted
- x-0-10-9-8-9, 8th fret, A, root position, top note C#, 1 open string
- x-12-11-12-13-x, 11th fret, A, root position, top note B#, all fretted
How to use A7#9
A7#9 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.
In a phrase:Em7→A7#9→Dmaj7— the ii–V–I of D.
Voice by voice, A7#9 → D. 2 voices move by a semitone, and one note is common to both chords.
| In A7#9 | 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 fifth | falls a whole tone | D, the root |
| G, the flat seventh | falls a semitone | F#, the major third |
| B#, the sharp ninth | rises a whole tone | D, the root |
What to play over A7#9
Every note of A7#9 is in A half-whole diminished.
Each of those is a page: the scale across the neck, and the chords it harmonises into — which is where A7#9 sits in it. Every scale.
Chords near A7#9
Change one note of A7#9 and you have Am7 (drop the major third), Am9 (the major third becomes the ninth), A7 (drop the sharp ninth), A9 (the sharp ninth becomes the ninth), A7b9 (the sharp ninth becomes the flat ninth) or A/G (drop the sharp ninth).
A7#9 is an altered chord — a dominant seventh with its fifth or ninth moved. Altered dominant chords on every root.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.