F# Diminished
Introduction
Enharmonic equivalent: F♯ is enharmonically equivalent to G♭. See Gb Diminished.
Notes
F# Diminished Inversions
| Position | Notes |
|---|---|
| Root Position | F#4 – A4 – C5 |
| 1st Inversion | A4 – C5 – F#5 |
| 2nd Inversion | C5 – F#5 – A5 |
Key Signature
The key of F# Diminished has 6 sharps: F♯, C♯, G♯, D♯, A♯, E♯.
Theory: Intervals
The F# Diminished is built by stacking intervals from the root note. The formula R-m3-d5 describes the scale degrees used. The intervals P1-m3-d5 show the distance between each note in the chord.
F# Diminished — Frequently Asked Questions
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.
Practice Tips
- Compare F# Minor and F# Diminished: only the fifth changes (C vs perfect fifth). Play both back to back — the extra compression is striking.
- The tritone between F# and C creates maximum tension — practice just this two-note interval to hear its characteristic sound.
- F# Diminished most naturally resolves up by half step: play F#dim then a chord whose root is F# raised by one semitone.
- Practice all inversions: F#–A–C, A–C–F#, C–F#–A.
- Use F# Diminished as a vii° chord: it is one semitone below F## Major — try F#dim → F## Major to feel this powerful classical resolution.
- In a major key, find where F# Diminished fits naturally as a passing chord between two diatonic chords a step apart.