What notes are in the Bbaug chord?

Bbaug is made of Bb, D and F# — the 1, 3 and #5 degrees of an augmented chord built on Bb.

What keys use the Bbaug chord?

No major or natural-minor key contains all 3 notes of Bbaug. Chords like this arrive as borrowed harmony — secondary dominants, harmonic-minor colour, or chromatic passing chords — rather than as one of a key's native chords.

How do you play Bbaug on guitar and piano?

This page shows Bbaug on guitar, piano, ukulele, bass, mandolin and banjo — 9 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.

Is Bbaug the same as A#aug?

Yes. Bbaug and A#aug are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Bbaug is the spelling this site treats as canonical.

Chord · Bb Augmented

B♭aug Chord

B♭aug is Bb, D and F# — unsettled, dreamlike; symmetrical.

Hear it

B♭aug on every instrument

The same 3 notes, 6 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.

What B♭aug is made of

Bb Augmented (Bb augmented) is built from the notes Bb, D, F#, with the interval pattern 1, 3, #5. A common augmented chord across many styles.

Stack 1, 3 and #5 on a root of B♭ and you get Bb, D and F#. That interval recipe is what makes the chord an augmented chord — move the same shape to another root and the character travels with it, which is why Caug sounds like a transposed B♭aug.

Augmented: Unsettled, dreamlike; symmetrical.

Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with B♭ rather than its enharmonic equivalent.

Keys that contain B♭aug

No major or natural-minor key contains all 3 of these notes — this one gets borrowed.

Chords like this one sit outside the diatonic set — they arrive as secondary dominants, borrowed chords or passing harmony. Browse every key to see which progressions pull it in.

Other chords on B♭

Same root, different colour.

B♭Bb Major B♭mBb Minor B♭dimBb Diminished B♭sus2Bb Suspended 2nd B♭sus4Bb Suspended 4th B♭5Bb Power Chord B♭6Bb Major 6th B♭m6Bb Minor 6th

The same augmented shape, moved

The identical interval recipe, built on other roots.

CaugC Augmented DaugD Augmented EaugE Augmented FaugF Augmented GaugG Augmented AaugA Augmented BaugB Augmented F♯augF# Augmented

Questions people ask about Bbaug

What notes are in the Bbaug chord?: Bbaug is made of Bb, D and F# — the 1, 3 and #5 degrees of an augmented chord built on Bb.
What keys use the Bbaug chord?: No major or natural-minor key contains all 3 notes of Bbaug. Chords like this arrive as borrowed harmony — secondary dominants, harmonic-minor colour, or chromatic passing chords — rather than as one of a key's native chords.
How do you play Bbaug on guitar and piano?: This page shows Bbaug on guitar, piano, ukulele, bass, mandolin and banjo — 9 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Is Bbaug the same as A#aug?: Yes. Bbaug and A#aug are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Bbaug is the spelling this site treats as canonical.

Learn the theory behind it

Why B♭aug behaves the way it does — the guides that explain the chord instead of just spelling it.

Barre Chords — The Wall Every Guitarist ClimbsThis one asks for a barre. The article is the fix for the buzzing and the aching hand.7 min read Borrowed Chords and Modal Mixture — Stealing from Parallel KeysThe raised fifth comes from outside the key. This is where chords like it are borrowed from.7 min read Functional Harmony: Three Roles, One EngineThat sharpened fifth is a pull toward the next chord — here is the mechanism.6 min read