F♯add9 — F♯, A♯, C♯, G♯ — is an add9 chord: major triad + 9th (no 7th in between) — a brighter alternative to a plain major chord, popular in pop, indie, and modern songwriting.
Intervals
The F# add 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#→G#perfect 5th7 semitones
On the keyboard
Each note of the F# add 9 chord highlighted on a piano. Pitch class is what matters — any octave works.
On the guitar
One voicing of the F# add 9 chord on a six-string guitar fretboard.
- 1F#
- 3A#
- 5C#
- 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 a bright tonic alternative in major-key pop, country, and modern songwriting.
Drill it
The F# add 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♯add9 chord?
- F♯add9 contains four notes: F♯, A♯, C♯, G♯.
- How is F♯add9 different from F♯maj7?
- F♯add9 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♯add9 used in music?
- Functions as a bright tonic alternative in major-key pop, country, and modern songwriting.