F♯9 — F♯, A♯, C♯, E, G♯ — is a dominant 9th chord: major triad + minor 7th + major 9th — a dominant chord with the 9th added on top for a rich, slightly bluesy colour.
Intervals
The F# dominant 9 chord stacks two thirds on the root. Each interval and its size in semitones:
- F#→A#major 3rd4 semitones
- A#→C#minor 3rd3 semitones
- C#→Eminor 3rd3 semitones
- E→G#major 3rd4 semitones
On the keyboard
Each note of the F# dominant 9 chord highlighted on a piano. Pitch class is what matters — any octave works.
On the guitar
One voicing of the F# dominant 9 chord on a six-string guitar fretboard.
- 1F#
- 3A#
- 5C#
- ♭7E
- 9G#
Common mistakes
The defining note is the 9th (G♯). It sits more than an octave above the root, which is why the chord needs a wide voicing — in tight piano voicings the 9th usually appears in the top register while the root and lower triad tones cluster below.
In context
Functions as the V9 in its target key — a richer, more colourful alternative to the plain V7 dominant.
Drill it
The F# dominant 9 chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.
Open the Chord Trainer →Or try today's Etudle puzzleRelated
Frequently asked
- What notes are in a F♯9 chord?
- F♯9 contains five notes: F♯, A♯, C♯, E, G♯.
- How is F♯9 different from F♯7?
- F♯9 adds the 9th (G♯) on top of the underlying 7th chord. The 9th extends the chord into the next octave and adds harmonic colour.
- When is F♯9 used in music?
- Functions as the V9 in its target key — a richer, more colourful alternative to the plain V7 dominant.