About the G sharp nine chord
G sharp nine is used in C sharp Major, where every note it holds is a scale tone. Think of it as a G♯ dominant ninth chord.
Its notes are G♯, B♯, D♯, F♯, and A♯. The intervals are a major third, a perfect fifth, a minor seventh, and a major ninth.
Also called A flat nine, which spells the same notes enharmonically.
Positions
Notes and intervals
| 1 | G#G♯ | Root |
|---|---|---|
| 2 | B#B♯ | Major 3rd |
| 3 | D#D♯ | Perfect 5th |
| 4 | F#F♯ | Minor 7th |
| 5 | A#A♯ | Major 9th |
Shapes
Chromatic
Circle of Fifths
Other G sharp chords
Simpler triads
Suspended
Sixths and sevenths
Extensions
Altered
Functional relationships
These chords are where this one most naturally comes from and resolves to inside a key.
Relative minor
The relative minor uses the same notes and key signature, so it works as a calmer, darker home base.
Parallel minor
The parallel minor keeps the same root note but lowers the third, giving the same key a darker, sadder sound.
Dominant
The dominant is a fifth above the root, and it builds tension that pulls strongly back to this chord.
Subdominant
The subdominant is a fourth above the root (a fifth below), and it usually leads on to the dominant or back home.
Tritone substitution
The tritone substitution is a dominant chord a tritone away that shares the same tension, so it can stand in for this chord and resolve the same way.