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 B Major, so the relevant key signature is that key’s — 5 sharps (F♯, C♯, G♯, D♯, A♯). Spelled as a scale, these notes are Gb Mixolydian.
F♯C♯G♯D♯A♯
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 B Major
These are the triads built on each degree of the B 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 Gb Dominant 9th chord?
The Gb Dominant 9th chord (Gb9) contains 5 notes: Gb, Bb, Db, E, Ab. Formula: R-M3-P5-m7-M9.
How is Gb9 used in music?
Gb9 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 Gb9?
Gb9 uses scale degrees 1-3-5-b7-9, giving it its distinctive sound.