The G♯ Dominant 9th chord is a five-note chord made up of G♯, B♯, D♯, F♯, and A♯. It is built from a root, major third, perfect fifth, minor seventh, and major ninth.
Construction
G♯ Dominant 9th = Root + Major 3rd + Perfect 5th + Minor 7th + Major 2nd = G♯ · B♯ · D♯ · F♯ · A♯
| Note | Interval | Degree |
|---|---|---|
| G♯ | Root | 1 |
| B♯ | Major 3rd | 3 |
| D♯ | Perfect 5th | 5 |
| F♯ | Minor 7th | ♭7 |
| A♯ | Major 2nd | 9 |
Key Signature
A dominant chord points home to the key a fifth below its root: the G♯ Dominant 9th is the V (dominant) of C# Major, so the relevant key signature is that key’s — 7 sharps (F♯, C♯, G♯, D♯, A♯, E♯, B♯). Spelled as a scale, these notes are G# Mixolydian.
F♯C♯G♯D♯A♯E♯B♯
Order of sharps
Sharps are added to a key signature in a fixed order. Each new sharp key adds the next sharp on the list.
F♯C♯G♯D♯A♯E♯B♯
Mnemonic: Father Charles Goes Down And Ends Battle
Chords in the Key of C♯ Major
These are the triads built on each degree of the C♯ major scale:
G♯ Dominant 9th — Frequently Asked Questions
What is the G♯ Dominant 9th chord on piano?
The G♯ Dominant 9th chord contains the notes G♯ – B♯ – D♯ – F♯ – A♯. On piano, play these notes together to sound the chord.
What notes are in the G# Dominant 9th chord?
The G# Dominant 9th chord (G#9) contains 5 notes: G#, C, D#, F#, A#. Formula: R-M3-P5-m7-M9.
How is G#9 used in music?
G#9 is used in jazz, fusion, and contemporary music to add harmonic color. It appears as a dominant or tonic chord depending on context.
What is the scale degree formula for G#9?
G#9 uses scale degrees 1-3-5-b7-9, giving it its distinctive sound.