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

Also called or written Fm7♭5, F or F Half Diminished Minor 7

F minor 7th flat 5th contains F, A♭, C♭ and E♭. The 1st-fret shape requires a wide stretch between the index and pinky fingers.

FC♭E♭A♭EADG
Positions on the neck1 of 4
Practice F minor 7th flat 5th chord

How it is built

FRootA♭Minor thirdC♭Diminished fifthE♭Minor seventh

Formula 1, ♭3, ♭5, ♭7

Inversions

How do you play an F minor 7th flat 5th chord on bass?

F minor 7th flat 5th is played at the 1st fret as 1 2 1 1: index finger on the E string at fret 1, pinky finger on the A string at fret 2, middle finger on the D string at fret 1 and ring finger on the G string at fret 1.

Full note and interval breakdown
StringFretFingerNote
4 (E)11F (1)
3 (A)24C♭ (♭5)
2 (D)12E♭ (♭7)
1 (G)13A♭ (♭3)

AdvancedThe wide stretch between the index finger on the 4th string and the pinky on the 3rd string at the 1st fret is the hardest part.

13th fret

F minor 7th flat 5th is played at the 13th fret as 13 14 13 13: index finger on the E string at fret 13, pinky finger on the A string at fret 14, middle finger on the D string at fret 13 and ring finger on the G string at fret 13.

Full note and interval breakdown
StringFretFingerNote
4 (E)131F (1)
3 (A)144C♭ (♭5)
2 (D)132E♭ (♭7)
1 (G)133A♭ (♭3)

Fm7♭5/C♭ inversion

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

Full note and interval breakdown
StringFretFingerNote
4 (E)72C♭ (♭5)
3 (A)83F (1)
2 (D)61A♭ (♭3)
1 (G)84E♭ (♭7)

Fm7♭5/E♭ inversion

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

Full note and interval breakdown
StringFretFingerNote
4 (E)113E♭ (♭7)
3 (A)114A♭ (♭3)
2 (D)91C♭ (♭5)
1 (G)102F (1)

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♭.

Other F chords

Common questions

How is F minor 7th flat 5th written?

F minor 7th flat 5th is written as Fm7♭5, and it is also called Half Diminished Minor 7.

What is the difference between F minor 7th flat 5th and F diminished?

F minor 7th flat 5th adds a minor 7th to the diminished triad. F diminished has only the root, ♭3 and ♭5.

Why does F minor 7th flat 5th sound unstable?

The tritone between F and C♭ creates tension that wants to resolve. This instability makes the chord useful as a passing harmony.