B minor 7th flat 5th chord on bass (Bm7♭5)

Why it sounds like that

B minor 7th flat 5th is built from the formula 1, ♭3, ♭5, ♭7. The diminished 5th between B and F gives the chord its tense, unresolved quality. Raising the ♭5 to a perfect 5th produces B minor 7th, the closest stable contrast.

What goes wrong with B minor 7th flat 5th?

• Letting the pinky collapse and mute the 2nd string.
• Fretting the 1st string with the ring finger too far from the fret, causing a buzz.
• Allowing the index finger to touch the 3rd string and deaden the B.

When to use it

B minor 7th flat 5th functions as the ii chord in A natural minor and the vii chord in C major. Use it in minor-key jazz and blues lines where the half-diminished colour leads to a dominant. It pairs naturally with B minor and B 5th.

Changing to and from B minor 7th flat 5th

• Sliding the shape down two frets to the 5th fret gives A minor 7th flat 5th.
• Sliding the shape up one fret to the 8th fret gives C minor 7th flat 5th.

Which voicing to use

The 7th-fret root position keeps B in the bass for a grounded sound. The Bm7♭5/F inversion at the 1st fret places the diminished 5th in the bass, creating a darker, less stable feel. Choose the Bm7♭5/A inversion when the bass line needs to descend to A.