Tools / Chords / B♭ 7th sharp 5

B♭ 7th sharp 5 chord on bass (B♭7♯5)

Also written B♭7♯5, B♭ or B♭ Dominant 7th ♯5

Bass · B♭7♯5/F♯ inversion · open position

B♭ 7th sharp 5 contains B♭, D, F♯, and A♭. The open D string makes the default voicing easier to fret than the other inversions.

B♭7♯5/F♯ inversion · open position2-1-0-1

Positions on the neck1 of 3

How it’s built

B♭1Root

D3Major 3rd

F♯♯5Augmented 5th

A♭♭7Minor 7th

Formula 1, 3, ♯5, ♭7

Positions on the neck1 of 3

Inversions

The same three notes, with a different one in the bass.

Root positionB♭–D–F♯–A♭B♭7♯5Bass B♭

First inversionD–F♯–A♭–B♭B♭7♯5/DBass D

Second inversionF♯–A♭–B♭–DB♭7♯5/F♯Bass F♯

Third inversionA♭–B♭–D–F♯B♭7♯5/A♭Bass A♭

Why it sounds like that

B♭ 7th sharp 5 is built from the formula 1, 3, ♯5, ♭7. The augmented 5th, F♯, creates a bright, tense sound. Compare it to B♭ 7th, which has a perfect 5th.

What goes wrong with B♭ 7th sharp 5?

Letting the ring finger touch the A string and mute it.
Pressing the index finger too flat and buzzing the A string.
Striking the open D string too hard and overpowering the fretted notes.

When to use it

B♭ 7th sharp 5 suits jazz, blues, and R&B lines that need a raised 5th. It pairs well with B♭ major and B♭ 7th.

Changing to and from B♭ 7th sharp 5

Sliding the shape down two frets to the 12th fret gives A♭ 7th sharp 5. Keep the finger spacing identical while shifting.
Move to B♭ 7th by fretting the D string at the 3rd fret instead of leaving it open; the other fingers stay in place.

Which voicing to use

The F♯ inversion puts the augmented 5th in the bass, giving a bright, unstable sound. The A♭ inversion has the ♭7 in the bass and is higher on the neck. Use the F♯ inversion for a more cutting tone.

How do you play a B♭ 7th sharp 5 chord on bass?

B♭7♯5/F♯ inversion · open position

Beginner● On the diagram

B♭ 7th sharp 5 is played in open position as 2 1 0 1: ring finger on the E string at fret 2, index finger on the A string at fret 1 and middle finger on the G string at fret 1. The D string rings open.

Tip — The ring finger must fret the 2nd fret on the E string while the index and middle hold the 1st fret on adjacent strings.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	2	3	F♯ (♯5)
3 (A)	1	1	B♭ (1)
2 (D)	open	—	D (3)
1 (G)	1	2	A♭ (♭7)

B♭7♯5/F♯ inversion · fret 12

Intermediate

B♭ 7th sharp 5 is played at the 12th fret as 14 13 12 13: pinky finger on the E string at fret 14, middle finger on the A string at fret 13, index finger on the D string at fret 12 and ring finger on the G string at fret 13.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	14	4	F♯ (♯5)
3 (A)	13	2	B♭ (1)
2 (D)	12	1	D (3)
1 (G)	13	3	A♭ (♭7)

B♭7♯5/A♭ inversion

Intermediate

B♭ 7th sharp 5 is played at the 3rd fret as 4 5 4 3: middle finger on the E string at fret 4, pinky finger on the A string at fret 5, ring finger on the D string at fret 4 and index finger on the G string at fret 3.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	4	2	A♭ (♭7)
3 (A)	5	4	D (3)
2 (D)	4	3	F♯ (♯5)
1 (G)	3	1	B♭ (1)

Common questions

How is B♭ 7th sharp 5 written?

B♭ 7th sharp 5 is written as B♭7♯5 or B♭7+5. The ASCII root is Bb, so you may see Bb7#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♭ 7th sharp 5 adds a minor 7th, A♭, to the augmented triad B♭–D–F♯. B♭ augmented has only the root, major 3rd, and augmented 5th. The 7th makes the chord dominant and more dissonant.

Can B♭ 7th sharp 5 be used as a passing chord?

B♭ 7th sharp 5 works as a passing chord between B♭ 7th and B♭ 9th. Its raised 5th creates tension that resolves to the next chord. Use it briefly on a weak beat.

String

Fret

Finger

Note

4 (E)

F♯ (♯5)

3 (A)

B♭ (1)

2 (D)

open

—

D (3)

1 (G)

A♭ (♭7)

String

Fret

Finger

Note

4 (E)

F♯ (♯5)

3 (A)

B♭ (1)

2 (D)

D (3)

1 (G)

A♭ (♭7)

String

Fret

Finger

Note

4 (E)

A♭ (♭7)

3 (A)

D (3)

2 (D)

F♯ (♯5)

1 (G)

B♭ (1)