B♭ augmented chord on ukulele (B♭aug)

Also called or written B♭aug or B♭+

B♭ augmented contains B♭, D, and F♯. Its 1st fret grip stretches the pinky to the 3rd fret while the index holds the 1st, making it a compact but demanding shape.

B♭DF♯B♭GCEA
Positions on the neck1 of 4
Practice B♭ augmented chord

How it is built

B♭RootDMajor thirdF♯Augmented fifth

Formula 1, 3, ♯5

Inversions

How do you play a B♭ augmented chord on ukulele?

B♭ augmented is played at the 1st fret as 3 2 2 1: pinky finger on the G string at fret 3, middle finger on the C string at fret 2, ring finger on the E string at fret 2 and index finger on the A string at fret 1.

Full note and interval breakdown
StringFretFingerNote
4 (G)34B♭ (1)
3 (C)22D (3)
2 (E)23F♯ (♯5)
1 (A)11B♭ (1)

IntermediateThe pinky must reach the 3rd fret on the 4th string while the other fingers hold frets 1 and 2 cleanly.

9th fret · ×-10-10-9

B♭ augmented is played at the 9th fret as × 10 10 9: middle finger on the C string at fret 10, ring finger on the E string at fret 10 and index finger on the A string at fret 9. The G string stays muted.

Full note and interval breakdown
StringFretFingerNote
4 (G)muted
3 (C)102B♭ (1)
2 (E)103D (3)
1 (A)91F♯ (♯5)

B♭aug/F♯ inversion

B♭ augmented is played at the 5th fret as 7 6 6 5: pinky finger on the G string at fret 7, middle finger on the C string at fret 6, ring finger on the E string at fret 6 and index finger on the A string at fret 5.

Full note and interval breakdown
StringFretFingerNote
4 (G)74D (3)
3 (C)62F♯ (♯5)
2 (E)63B♭ (1)
1 (A)51D (3)

9th fret · 11-10-10-9

B♭ augmented is played at the 9th fret as 11 10 10 9: pinky finger on the G string at fret 11, middle finger on the C string at fret 10, ring finger on the E string at fret 10 and index finger on the A string at fret 9.

Full note and interval breakdown
StringFretFingerNote
4 (G)114F♯ (♯5)
3 (C)102B♭ (1)
2 (E)103D (3)
1 (A)91F♯ (♯5)

Why it sounds like that

B♭ augmented is built from a major 3rd between B♭ and D, and an augmented 5th between B♭ and F♯. The raised fifth creates the chord's tense, symmetrical quality. Compare it to B♭ major, where the fifth is natural.

What goes wrong with B♭ augmented?

  • Letting the pinky collapse and buzz the 4th string.
  • Pressing the middle finger too flat and deadening the 2nd string.
  • Strumming before the index finger fully frets the 1st string.

When to use it

B♭ augmented works as a passing chord in B♭ major progressions, such as B♭–B♭aug–E♭, the I–I+–IV. Its unstable sound suits jazz and blues turnarounds. Use it with B♭ major or B♭ 7th.

Changing to and from B♭ augmented

  • Sliding the shape up one fret to the 2nd fret gives B augmented.
  • Sliding the shape up two frets to the 3rd fret gives C augmented.

Which voicing to use

The 1st fret voicing puts B♭ in the bass and is the most compact. The 9th fret version mutes the 4th string and sounds brighter. For a D bass, use the B♭aug/D inversion at the 5th fret.

Other B♭ chords

Common questions

How is B♭ augmented written?

B♭ augmented is written as B♭+ or B♭aug. On a keyboard, type Bb+ or Bbaug. It is also spelled A♯ in enharmonic notation for the same sounding root.

Why does B♭ augmented sound unstable?

B♭ augmented has an augmented 5th, F♯, which creates tension. The chord's two major 3rds divide the octave symmetrically. This symmetry makes it want to resolve.

What is the difference between B♭ augmented and B♭ major?

B♭ major has a perfect 5th, F, while B♭ augmented raises that to F♯. The raised fifth gives B♭ augmented its distinctive unsettled sound.