B♭ 7th flat 5 chord on ukulele (B♭7♭5)

Also called or written B♭7♭5, B♭, B♭ Dominant 7th Flat 5 or B♭ 7th ♭5

B♭ 7th flat 5 contains B♭, D, F♭, and A♭. The 3rd fret shape demands a pinky reach to fret 5 on the A string, making it a stretchy advanced grip.

3frB♭F♭A♭DGCEA
Positions on the neck1 of 4
Practice B♭ 7th flat 5 chord

How it is built

B♭RootDMajor thirdF♭Diminished fifthA♭Minor seventh

Formula 1, 3, ♭5, ♭7

Inversions

How do you play a B♭ 7th flat 5 chord on ukulele?

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

Full note and interval breakdown
StringFretFingerNote
4 (G)31B♭ (1)
3 (C)42F♭ (♭5)
2 (E)43A♭ (♭7)
1 (A)54D (3)

AdvancedThe pinky must stretch to fret 5 on the A string while the other fingers hold frets 3 and 4 cleanly.

B♭7♭5/A♭ inversion

B♭ 7th flat 5 is played at the 6th fret as 7 8 6 7: middle finger on the G string at fret 7, pinky finger on the C string at fret 8, index finger on the E string at fret 6 and ring finger on the A string at fret 7.

Full note and interval breakdown
StringFretFingerNote
4 (G)72D (3)
3 (C)84A♭ (♭7)
2 (E)61B♭ (1)
1 (A)73F♭ (♭5)

9th fret

B♭ 7th flat 5 is played at the 9th fret as 9 10 10 11: index finger on the G string at fret 9, middle finger on the C string at fret 10, ring finger on the E string at fret 10 and pinky finger on the A string at fret 11.

Full note and interval breakdown
StringFretFingerNote
4 (G)91F♭ (♭5)
3 (C)102B♭ (1)
2 (E)103D (3)
1 (A)114A♭ (♭7)

B♭7♭5/D inversion

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

Full note and interval breakdown
StringFretFingerNote
4 (G)11A♭ (♭7)
3 (C)23D (3)
2 (E)openF♭ (♭5)
1 (A)12B♭ (1)

Why it sounds like that

B♭ 7th flat 5 is built from the formula 1, 3, ♭5, ♭7. The diminished 5th between B♭ and F♭ gives the chord its tense, unresolved quality. Compared to B♭ 7th, the perfect 5th is lowered by one semitone.

What goes wrong with B♭ 7th flat 5?

  • The pinky flattens and mutes the A string at fret 5.
  • The index finger lifts off the G string, causing a buzz.

When to use it

Use the supplied linked chords to hear its tension without adding unsupported harmony. It suits jazz and blues where a darker, unresolved color is needed. Pair it with B♭ major for a quick release of tension.

Changing to and from B♭ 7th flat 5

  • Sliding the shape down two frets to the 1st fret gives A♭ 7th flat 5.
  • Sliding the shape up two frets to the 5th fret gives C 7th flat 5.

Which voicing to use

The 3rd fret position keeps B♭ in the bass for a root-position sound. The B♭7♭5/A♭ inversion at frets 1-2-0-1 puts A♭ in the bass and is the easiest shape to grab. The B♭7♭5/D inversion at frets 7-8-6-7 places D in the bass for a brighter register.

Other B♭ chords

Common questions

How is B♭ 7th flat 5 written?

B♭ 7th flat 5 is written as B♭7♭5 or B♭7-5. The ASCII root is Bb, so Bb7b5 also works. It is also spelled A♯ in enharmonic notation for the same sounding root.

What is the difference between B♭ 7th flat 5 and B♭ 7th?

B♭ 7th has a perfect 5th (F), while B♭ 7th flat 5 lowers that note to F♭. This creates a diminished 5th interval and a more dissonant sound.

Why does B♭ 7th flat 5 sound so tense?

The chord contains a tritone between B♭ and F♭, which is highly unstable. This tension makes it want to resolve to a more consonant chord.