G7b9 G dominant seventh flat nine chord
- Notes
- G B D F Ab
- Formula
- 1 3 5 b7 b9
- Semitones
- 0 4 7 10 13 above the root
- Other symbols
- G7(b9), G7-9
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 Ab is a minor third (3 semitones). A dominant seventh with a flattened ninth, Ab, 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.
G7b9 on the piano
Root position from G4: G4, B4, D5, F5, Ab5. Middle C is C4.
G7b9 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.
3 x 3 4 3 4 (low E to high e)
Sounds G2 F3 B3 D4 Ab4
x 10 9 10 9 x (low E to high e)
Sounds G3 B3 F4 Ab4, 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 G7b9
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 Ab | G7b9 | |
| 1st inversion | B D F Ab G | G7b9/B | |
| 2nd inversion | D F Ab G B | G7b9/D | |
| 3rd inversion | F Ab G B D | G7b9/F | |
| 4th inversion | Ab G B D F | G7/Ab (also read as G7b9/Ab) |
Where G7b9 fits
G7b9 is V7b9 in C minor. Its upper four notes B D F Ab are Bdim7, so G7b9 and that diminished seventh are interchangeable over a G bass. The flat ninth Ab falls a half step to the fifth of Cm.