B♭ Augmented Triad

Chord Tones: B♭ Augmented Triad

Symbol: aug, + — Formula: 1-3-♯5

Chord Notation

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

Inversions

Harmonic Function

The B♭ 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. The B♭ Augmented Triad specifically contains 3 notes: B♭, D, G♭ (formula: 1-3-♯5). On piano, Bb-rooted chords start on a black key and create hand shapes that jazz pianists find ideal for voicing seventh chords and extended harmonies. Jazz standards, swing, and big band charts are heavily weighted toward Bb because it allows horn sections to play in their most comfortable range.

Common Progressions

The B♭ Augmented Triad frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

• Iaug-IV
• Vaug-I

Songs Featuring the Augmented Triad

Well-known songs where the B♭ Augmented Triad — or this chord type — plays a prominent role:

• Oh! You Pretty Things – David Bowie
• All Blues – Miles Davis
• Michelle – The Beatles

Tuning Frequencies Across Temperaments

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

Scales Containing the B♭ Augmented Triad

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