G#7b9 G# dominant seventh flat nine chord
- Notes
- G# B# D# F# A
- Formula
- 1 3 5 b7 b9
- Semitones
- 0 4 7 10 13 above the root
- Also written
- Ab7b9 (Ab C Eb Gb Bbb)
- Other symbols
- G#7(b9), G#7-9
G# to B# is a major third (4 semitones), B# to D# is a minor third (3 semitones), D# to F# is a minor third (3 semitones), F# to A is a minor third (3 semitones). A dominant seventh with a flattened ninth, A, a half step (plus an octave) above the root. It is the sharpest-sounding of the common dominant chords and pulls hard towards a minor tonic.
G#7b9 on the piano
Root position from G#4: G#4, B#4, D#5, F#5, A5. Middle C is C4.
G#7b9 on the guitar
Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has G# as its lowest note.
4 x 4 5 4 5 (low E to high e)
Sounds G#2 F#3 B#3 D#4 A4
x 11 10 11 10 x (low E to high e)
Sounds G#3 B#3 F#4 A4, fifth left out
The E-shape and A-shape grips are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play dominant seventh flat nine chords on other roots.
Inversions of G#7b9
An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.
| Position | Notes, bass first | Named | Listen |
|---|---|---|---|
| Root position | G# B# D# F# A | G#7b9 | |
| 1st inversion | B# D# F# A G# | G#7b9/C | |
| 2nd inversion | D# F# A G# B# | G#7b9/D# | |
| 3rd inversion | F# A G# B# D# | G#7b9/F# | |
| 4th inversion | A G# B# D# F# | Ab7/A (also written G#7/A; also read as G#7b9/A) |
Where G#7b9 fits
G#7b9 is V7b9 in C# minor. Its upper four notes B# D# F# A are Cdim7, so G#7b9 and that diminished seventh are interchangeable over a G# bass. The flat ninth A falls a half step to the fifth of C#m.