F# Diminished Triad

Chord Tones: F# Diminished Triad

Symbol: dim, ° — Formula: 1-♭3-♭5

DegreeNoteFrequency (A=440, Equal)
1 F# 369.994 Hz
♭3 A 440.000 Hz
♭5 C 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# A C F# F# Diminished Triad
First Inversion A C F# A F# Diminished Triad/A
Second Inversion C F# A 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.

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# 369.994 Hz 371.251 Hz 367.911 Hz
A 440.000 Hz 440.000 Hz 436.043 Hz
C 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: