Explore chords · Ukulele
B♭ 7th sharp 5 chord on ukulele (B♭7♯5)
Also called or written B♭7♯5, B♭ or B♭ Dominant 7th ♯5
B♭ 7th sharp 5 is built from B♭, D, F♯ and A♭. The 11-10-10-11 grip sits high on the neck and demands a clean four-finger stretch.
How it is built
Formula 1, 3, ♯5, ♭7
- Root positionB♭–D–F♯–A♭B♭7♯511-10-10-11
- First inversionD–F♯–A♭–B♭B♭7♯5/D1-2-2-1
- Second inversionF♯–A♭–B♭–DB♭7♯5/F♯11-10-10-11
- Third inversionA♭–B♭–D–F♯B♭7♯5/A♭1-2-2-1
How do you play a B♭ 7th sharp 5 chord on ukulele?
B♭ 7th sharp 5 is played at the 10th fret as 11 10 10 11: ring finger on the G string at fret 11, index finger on the C string at fret 10, middle finger on the E string at fret 10 and pinky finger on the A string at fret 11.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 11 | 3 | F♯ (♯5) |
| 3 (C) | 10 | 1 | B♭ (1) |
| 2 (E) | 10 | 2 | D (3) |
| 1 (A) | 11 | 4 | A♭ (♭7) |
AdvancedThe four-finger stretch across frets 10 and 11, with the pinky reaching fret 11 on the A string, is the hardest part.
B♭7♯5/D inversion
B♭ 7th sharp 5 is played at the 1st fret as 1 2 2 1: index finger on the G string at fret 1, ring finger on the C string at fret 2, pinky finger on the E string at fret 2 and middle finger on the A string at fret 1.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 1 | 1 | A♭ (♭7) |
| 3 (C) | 2 | 3 | D (3) |
| 2 (E) | 2 | 4 | F♯ (♯5) |
| 1 (A) | 1 | 2 | B♭ (1) |
Why it sounds like that
B♭ 7th sharp 5 stacks a major 3rd, an augmented 5th and a minor 7th over the root. The augmented 5th, F♯, is what separates it from B♭ 7th, whose 5th is F natural. That raised 5th creates a tritone with the 3rd, D, giving the chord its tense dominant colour.
What goes wrong with B♭ 7th sharp 5?
- Letting the pinky flatten onto the A string and deaden the note at fret 11.
- Not arching the ring finger enough, causing the G string at fret 11 to buzz.
When to use it
B♭ 7th sharp 5 works as a tense dominant in jazz or blues, especially over B♭ aeolian dominant or B♭ altered scales. Use it to add tension before resolving to B♭ major.
Changing to and from B♭ 7th sharp 5
- Sliding the shape down two frets to the 8th fret gives A♭ 7th sharp 5.
Which voicing to use
The default B♭7♯5/F♯ inversion puts the augmented 5th in the bass, which makes the chord sound unstable and restless. The B♭7♯5/A♭ inversion, with the ♭7 in the bass, is lower and slightly darker.
Other B♭ chords
Common questions
How is B♭ 7th sharp 5 written?
B♭ 7th sharp 5 is written as B♭7♯5 or B♭. The ASCII root is Bb, so Bb7#5 also works. It is also called Dominant 7th ♯5. It is also spelled A♯ in enharmonic notation for the same sounding root.
What is the difference between B♭ 7th sharp 5 and B♭ augmented?
B♭ augmented has no 7th: it is B♭, D and F♯. B♭ 7th sharp 5 adds the minor 7th, A♭, which makes it a dominant chord rather than a pure augmented triad.
Why does B♭ 7th sharp 5 sound so tense?
The augmented 5th, F♯, forms a tritone with the 3rd, D. That tritone is the engine of dominant tension, pulling the chord toward its resolution.