F minor 7th flat 5th chord on bass (Fm7♭5)

Why it sounds like that

F minor 7th flat 5th is built from the formula 1, ♭3, ♭5, ♭7. The diminished 5th between F and C♭ creates the chord's characteristic tension. Raising the ♭5 to a perfect 5th produces F minor 7th, the closest stable contrast.

What goes wrong with F 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 F.

When to use it

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

Changing to and from F minor 7th flat 5th

• Sliding the shape up one fret to the 2nd fret gives F♯ minor 7th flat 5th.
• Sliding the shape up two frets to the 3rd fret gives G minor 7th flat 5th.

Which voicing to use

The 1st-fret root position keeps F in the bass for a grounded sound. The Fm7♭5/C♭ inversion at the 7th fret places the diminished 5th in the bass, creating a darker, less stable feel. Choose the Fm7♭5/E♭ inversion when the bass line needs to descend to E♭.