F♯ Augmented Triad

Chord Tones: F♯ Augmented Triad

Symbol: aug, + — Formula: 1-3-♯5

DegreeNoteFrequency (A=440, Equal)
1 F♯4 369.994 Hz
3 A♯4 466.164 Hz
♯5 D4 293.665 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolF♯aug
All Common Symbolsaug, +
Interval Formula1-3-♯5
Harmonic Categoryunstable

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 A♯4 D4 F♯ F♯ Augmented Triad
First Inversion A♯4 D4 F♯4 A♯ F♯ Augmented Triad/A♯
Second Inversion D4 F♯4 A♯4 D F♯ Augmented Triad/D

Harmonic Function

The F♯ augmented 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 augmented triad consists of two stacked major thirds, creating a symmetrical, ambiguous chord. Its raised fifth gives it a tense, unresolved quality that pulls toward resolution. The F♯ Augmented Triad specifically contains 3 notes: F♯, A♯, D (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♯ Augmented Triad frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

Songs Featuring the Augmented Triad

Well-known songs where the F♯ Augmented 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
A♯4 466.164 Hz 463.538 Hz 470.926 Hz
D4 293.665 Hz 293.332 Hz 294.329 Hz

Scales Containing the F♯ Augmented Triad

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