B Augmented Seventh Chord

Chord Tones: B Augmented Seventh Chord

Symbol: aug7, +7, 7♯5 — Formula: 1-3-♯5-♭7

DegreeNoteFrequency (A=440, Equal)
1 B4 493.883 Hz
3 D♯4 311.127 Hz
♯5 G4 391.995 Hz
♭7 A4 440.000 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolBaug7
All Common Symbolsaug7, +7, 7♯5
Interval Formula1-3-♯5-♭7
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 B4 D♯4 G4 A4 B B Augmented Seventh Chord
First Inversion D♯4 G4 A4 B4 D♯ B Augmented Seventh Chord/D♯
Second Inversion G4 A4 B4 D♯4 G B Augmented Seventh Chord/G
Third Inversion A4 B4 D♯4 G4 A B Augmented Seventh Chord/A

Harmonic Function

The B augmented seventh chord commonly functions as the leading tone (vii) in C major or dominant (V) in E major. Its harmonic role varies by key — in major keys it provides extended harmonic tension.

The augmented seventh chord adds a minor seventh to the augmented triad, combining the restlessness of an augmented fifth with the tension of a dominant seventh. Used for maximum harmonic tension. The B Augmented Seventh Chord specifically contains 4 notes: B, D♯, G, A (formula: 1-3-♯5-♭7). On guitar, B-rooted chords are typically played as barre chords at the second or seventh fret, and on piano they use a comfortable mix of black and white keys. K-pop, J-pop, and modern R&B productions frequently feature B-rooted chords, chosen for how the key sits within typical vocal ranges.

Common Progressions

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

Songs Featuring the Augmented Seventh Chord

Well-known songs where the B Augmented Seventh Chord — 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
B4 493.883 Hz 495.000 Hz 490.548 Hz
D♯4 311.127 Hz 309.026 Hz 313.951 Hz
G4 391.995 Hz 391.111 Hz 392.438 Hz
A4 440.000 Hz 440.000 Hz 436.043 Hz

Scales Containing the B Augmented Seventh Chord

These scales include the B Augmented Seventh Chord as a diatonic or characteristic chord: