F♯ Diminished Triad

Chord Tones: F♯ Diminished Triad

Symbol: dim, ° — Formula: 1-♭3-♭5

DegreeNoteFrequency (A=440, Equal)
1 F♯4 369.994 Hz
♭3 A4 440.000 Hz
♭5 C4 261.626 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolF♯dim
All Common Symbolsdim, °
Interval Formula1-♭3-♭5
Harmonic Categorydissonant

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

InversionNotes (low to high)Bass NoteSlash Notation
Root Position F♯4 A4 C4 F♯ F♯ Diminished Triad
First Inversion A4 C4 F♯4 A F♯ Diminished Triad/A
Second Inversion C4 F♯4 A4 C F♯ Diminished Triad/C

Harmonic Function

The F♯ diminished chord commonly functions as the tritone substitution in C major or tonic in F♯ major. Its harmonic role varies by key — in major keys it provides stable harmonic grounding.

The diminished triad features a flat third and flat fifth, creating a tense, unstable sound. It occurs naturally on the seventh degree of the major scale and resolves strongly to the tonic. The F♯ Diminished Triad specifically contains 3 notes: F♯, A, C (formula: 1-♭3-♭5). On piano, F#-rooted chords place the root on a black key, creating hand positions that many pianists find ergonomically comfortable for fast passages. Progressive rock, jazz fusion, and electronic music use F#-rooted chords to create unexpected harmonic shifts and chromatic modulations.

Common Progressions

The F♯ Diminished Triad frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

Songs Featuring the Diminished Triad

Well-known songs where the F♯ Diminished Triad — or this chord type — plays a prominent role:

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

NoteEqual Temp.PythagoreanJust Intonation
F♯4 369.994 Hz 371.251 Hz 367.911 Hz
A4 440.000 Hz 440.000 Hz 436.043 Hz
C4 261.626 Hz 260.740 Hz 261.626 Hz

Scales Containing the F♯ Diminished Triad

These scales include the F♯ Diminished Triad as a diatonic or characteristic chord: