Bb Augmented Triad

Chord Tones: Bb Augmented Triad

Symbol: aug, + — Formula: 1-3-♯5

DegreeNoteFrequency (A=440, Equal)
1 Bb 466.164 Hz
3 D 293.665 Hz
♯5 Gb 369.994 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolBbaug
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 Bb D Gb Bb Bb Augmented Triad
First Inversion D Gb Bb D Bb Augmented Triad/D
Second Inversion Gb Bb D Gb Bb Augmented Triad/Gb

Harmonic Function

The Bb augmented chord commonly functions as the subtonic (♭VII) in C major or subdominant 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.

Common Progressions

The Bb 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 Bb 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
Bb 466.164 Hz 463.538 Hz 470.926 Hz
D 293.665 Hz 293.332 Hz 294.329 Hz
Gb 369.994 Hz 371.251 Hz 367.911 Hz

Scales Containing the Bb Augmented Triad

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