What notes are in a B♭ augmented chord?

B♭ augmented contains three notes: B♭ (the root), D (the major third), and F♯ (the augmented fifth).

Is B♭ augmented the same as D augmented?

Enharmonically yes — same three pitches in different inversions. B♭+, D+, and F♯+ all share B♭, D, and F♯ in pitch class.

How is B♭+ different from B♭ major?

Only the fifth changes. B♭ major is B♭–D–F; B♭+ raises the F to F♯. The half-step shift creates the augmented fifth and the chord's suspended quality.

Where does B♭ augmented appear in music?

In G minor harmonic-minor cadences (as III+) — Mozart's K. 550 G minor symphony uses similar augmented colours. In E♭ major, B♭+ functions as an altered dominant for a more dramatic resolution to the tonic.

Bb augmented chord — notes, intervals, and practice

B♭ augmented — B♭, D, F♯ — stacks two major thirds. B♭+ is enharmonically the same chord as D+ and F♯+ (= G♭+) in inversion. The chord functions as III+ of G harmonic minor and as an altered V in E♭ major.

Intervals

The Bb augmented chord stacks two thirds on the root. Each interval and its size in semitones:

Bb→Dmajor 3rd4 semitones
D→F#major 3rd4 semitones
Bb→F#augmented 5th8 semitones

On the keyboard

Each note of the Bb augmented chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the Bb augmented chord on a six-string guitar fretboard.

Common mistakes

B♭+ has B♭ and D as the lower notes (matching B♭ major) but the fifth is F♯, not F natural. The mix of one flat (B♭) and one sharp (F♯) is unusual visually — most chords use only one accidental type. Replacing F♯ with F makes a B♭ major chord; the augmented colour vanishes.

In context

B♭+ functions as III+ of G harmonic minor: Gm → B♭+ → E♭ (i → III+ → VI) is a colour cadence Mozart and Schubert both used in their G-minor works. As an altered V in E♭ major, B♭+ resolves to E♭ with F♯ leading up to G in the tonic.

Drill it

The Bb augmented chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

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Frequently asked

What notes are in a B♭ augmented chord?: B♭ augmented contains three notes: B♭ (the root), D (the major third), and F♯ (the augmented fifth).
Is B♭ augmented the same as D augmented?: Enharmonically yes — same three pitches in different inversions. B♭+, D+, and F♯+ all share B♭, D, and F♯ in pitch class.
How is B♭+ different from B♭ major?: Only the fifth changes. B♭ major is B♭–D–F; B♭+ raises the F to F♯. The half-step shift creates the augmented fifth and the chord's suspended quality.
Where does B♭ augmented appear in music?: In G minor harmonic-minor cadences (as III+) — Mozart's K. 550 G minor symphony uses similar augmented colours. In E♭ major, B♭+ functions as an altered dominant for a more dramatic resolution to the tonic.