The F♯ Diminished chord is a three-note chord made up of F♯, A, and C. It is built from a root, minor third, and diminished fifth.
Construction
F♯ Diminished = Root + Minor 3rd + Diminished 5th = F♯ · A · C
| Note | Interval | Degree |
|---|---|---|
| F♯ | Root | 1 |
| A | Minor 3rd | ♭3 |
| C | Diminished 5th | ♭5 |
F♯ Diminished Inversions
| Position | Notes |
|---|---|
| Root Position | F♯ – A – C |
| 1st Inversion | A – C – F♯ |
| 2nd Inversion | C – F♯ – A |
Key Signature
A Diminished chord is built from symmetrical or ambiguous intervals, so it doesn’t belong to a single key and has no key signature of its own.
How F♯ Diminished functions in a key
The same chord takes on a different harmonic role depending on the key it appears in. Here is where F♯ Diminished sits diatonically across the common keys:
- In G major, F♯ Diminished is the vii° chord — the dominant.
- In E minor, F♯ Diminished is the ii° chord — a predominant.
F♯ Diminished — Frequently Asked Questions
What is the F♯ Diminished chord on piano?
The F♯ Diminished chord contains the notes F♯ – A – C. On piano, play these notes together to sound the chord.
What notes are in the F# Diminished chord?
The F# Diminished chord contains: F# (root), A (minor third), and C (diminished fifth). Both intervals are compressed: the minor third is 3 semitones above the root, and the diminished fifth is 6 semitones — a tritone.
How does F# Diminished differ from F# Minor?
F# Minor has a perfect fifth. F# Diminished lowers the fifth by one semitone to C (diminished fifth). That extra compression creates intense harmonic tension — the tritone between root and diminished fifth is the most dissonant interval in Western music.
What is the symbol for the F# Diminished?
F# Diminished is written as F#dim or F#°. The ° or "dim" symbol means both the third and fifth are minor/diminished. Do not confuse with F#dim7 or F#ø (half-diminished), which include additional notes.
What are the inversions of F# Diminished?
First inversion (F# Diminished/A): A–C–F#. Second inversion (F# Diminished/C): C–F#–A. Diminished triads are used in classical music as the vii° chord — the chord one semitone below the tonic, with strong resolution pull.
How is F# Diminished used in music?
F# Diminished most commonly functions as the vii° chord in a major key, creating strong resolution back to the tonic. It also works as a chromatic passing chord between two nearby chords, and in classical music as a brief point of dissonance. Jazz uses the full four-note dim7 more often than the triad.
What songs use diminished chords?
Michelle (Beatles) uses a diminished chord as a chromatic passing chord. Many classical pieces use vii°–I cadences. Jazz standards use dim7 chords as chromatic passing and approach chords. Diminished harmony also appears in flamenco and film music for dramatic tension.