The D Dominant 9th chord is a five-note chord made up of D, F♯, A, C, and E. It is built from a root, major third, perfect fifth, minor seventh, and major ninth.
Construction
D Dominant 9th = Root + Major 3rd + Perfect 5th + Minor 7th + Major 2nd = D · F♯ · A · C · E
| Note | Interval | Degree |
|---|---|---|
| D | Root | 1 |
| F♯ | Major 3rd | 3 |
| A | Perfect 5th | 5 |
| C | Minor 7th | ♭7 |
| E | Major 2nd | 9 |
Key Signature
A dominant chord points home to the key a fifth below its root: the D Dominant 9th is the V (dominant) of G Major, so the relevant key signature is that key’s — 1 sharp (F♯). Spelled as a scale, these notes are D Mixolydian.
F♯
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 G Major
These are the triads built on each degree of the G major scale:
D Dominant 9th — Frequently Asked Questions
What is the D Dominant 9th chord on piano?
The D Dominant 9th chord contains the notes D – F♯ – A – C – E. On piano, play these notes together to sound the chord.
What notes are in the D Dominant 9th chord?
The D Dominant 9th chord (D9) contains 5 notes: D, F#, A, C, E. Formula: R-M3-P5-m7-M9.
How is D9 used in music?
D9 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 D9?
D9 uses scale degrees 1-3-5-b7-9, giving it its distinctive sound.