F♯ minor 7th flat 5th chord on bass (F♯m7♭5)

Also called or written F♯m7♭5, F♯ or F♯ Half Diminished Minor 7

F♯ minor 7th flat 5th contains F♯, A, C and E. The 2nd-fret shape spreads four fingers across two frets, demanding a wide left-hand stretch.

2frF♯CEAEADG
Positions on the neck1 of 4
Practice F♯ minor 7th flat 5th chord

How it is built

F♯RootAMinor thirdCDiminished fifthEMinor 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 2nd fret as 2 3 2 2: index finger on the E string at fret 2, pinky finger on the A string at fret 3, middle finger on the D string at fret 2 and ring finger on the G string at fret 2.

Full note and interval breakdown
StringFretFingerNote
4 (E)21F♯ (1)
3 (A)34C (♭5)
2 (D)22E (♭7)
1 (G)23A (♭3)

AdvancedThe wide stretch between the index finger on the 4th string and the pinky on the 3rd string at the 2nd fret is the hardest part.

14th fret

F♯ minor 7th flat 5th is played at the 14th fret as 14 15 14 14: index finger on the E string at fret 14, pinky finger on the A string at fret 15, middle finger on the D string at fret 14 and ring finger on the G string at fret 14.

Full note and interval breakdown
StringFretFingerNote
4 (E)141F♯ (1)
3 (A)154C (♭5)
2 (D)142E (♭7)
1 (G)143A (♭3)

F♯m7♭5/C inversion

F♯ minor 7th flat 5th is played at the 7th fret as 8 9 7 9: middle finger on the E string at fret 8, ring finger on the A string at fret 9, index finger on the D string at fret 7 and pinky finger on the G string at fret 9.

Full note and interval breakdown
StringFretFingerNote
4 (E)82C (♭5)
3 (A)93F♯ (1)
2 (D)71A (♭3)
1 (G)94E (♭7)

F♯m7♭5/E inversion

F♯ minor 7th flat 5th is played at the 10th fret as 12 12 10 11: ring finger on the E string at fret 12, pinky finger on the A string at fret 12, index finger on the D string at fret 10 and middle finger on the G string at fret 11.

Full note and interval breakdown
StringFretFingerNote
4 (E)123E (♭7)
3 (A)124A (♭3)
2 (D)101C (♭5)
1 (G)112F♯ (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 gives the chord its tense, unresolved quality. 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 G 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 down one fret to the 1st fret gives F minor 7th flat 5th.
  • Sliding the shape up one fret to the 3rd fret gives G minor 7th flat 5th.

Which voicing to use

The 2nd-fret root position keeps F♯ in the bass for a grounded sound. The F♯m7♭5/C inversion at the 8th fret places the diminished 5th in the bass, creating a darker, less stable feel. Choose the F♯m7♭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 F♯m7♭5, and it is also called Half Diminished Minor 7. The ASCII root spelling is F#. It is also spelled G♭ in enharmonic notation for the same sounding root.

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.