A9♯5 (augmented ninth)

5-note augmented 9th on AA, B, C♯, F, G.

Press to hear the chord strummed low to high.

A dominant ninth on an augmented triad — raised fifth plus ninth, tense and shimmering.

The notes

Pitches taken from the first fingering below — click any note to open its frequency page.

Interval formula

DegreeNoteWhat it is
1Aroot
9Bninth
3C♯major third
♯5Fsharp fifth (augmented)
♭7Gflat seventh (dominant)

The formula reads in semitones above the root (A): 1, 9, 3, ♯5, ♭7. A voicing may leave a tone out — often the fifth — but never adds one from outside this set.

Guitar fingerings · 4

2413
open position
3fr3214
from fret 3
5fr1234
from fret 5
11fr2134
from fret 11

Ukulele fingerings · 4

2
open position
3fr2413
from fret 3
6fr1223
from fret 6
9fr2413
from fret 9

Read a diagram top-down: the thick bar is the nut, dots are where to press (the number is which finger), means play the open string, means don't play it. A bar across strings is a barre.

Other A chords

9♯5 (augmented ninth) chords on every root