F♯ diminished 7th chord on bass (F♯dim7)

Also called or written F♯dim7 or F♯°7

F♯ diminished 7th contains F♯, A, C, and E♭. Its 1st fret position requires a wide stretch across all four strings.

F♯CE♭AEADG
Positions on the neck1 of 5
Practice F♯ diminished 7th chord

How it is built

F♯RootAMinor thirdCDiminished fifthE♭Minor seventh

Formula 1, ♭3, ♭5, ♭♭7

Inversions

How do you play an F♯ diminished 7th chord on bass?

F♯ diminished 7th is played at the 1st fret as 2 3 1 2: middle finger on the E string at fret 2, pinky finger on the A string at fret 3, index finger on the D string at fret 1 and ring finger on the G string at fret 2.

Full note and interval breakdown
StringFretFingerNote
4 (E)22F♯ (1)
3 (A)34C (♭5)
2 (D)11E♭ (6)
1 (G)23A (♭3)

AdvancedThe span from the index finger on the 2nd string to the pinky on the 3rd string requires significant finger independence.

13th fret

F♯ diminished 7th is played at the 13th fret as 14 15 13 14: middle finger on the E string at fret 14, pinky finger on the A string at fret 15, index finger on the D string at fret 13 and ring finger on the G string at fret 14.

Full note and interval breakdown
StringFretFingerNote
4 (E)142F♯ (1)
3 (A)154C (♭5)
2 (D)131E♭ (6)
1 (G)143A (♭3)

F♯dim7/A inversion

F♯ diminished 7th is played at the 4th fret as 5 6 4 5: middle finger on the E string at fret 5, pinky finger on the A string at fret 6, index finger on the D string at fret 4 and ring finger on the G string at fret 5.

Full note and interval breakdown
StringFretFingerNote
4 (E)52A (♭3)
3 (A)64E♭ (6)
2 (D)41F♯ (1)
1 (G)53C (♭5)

F♯dim7/C inversion

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

Full note and interval breakdown
StringFretFingerNote
4 (E)82C (♭5)
3 (A)94F♯ (1)
2 (D)71A (♭3)
1 (G)83E♭ (6)

F♯dim7/E♭ inversion

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

Full note and interval breakdown
StringFretFingerNote
4 (E)112E♭ (6)
3 (A)124A (♭3)
2 (D)101C (♭5)
1 (G)113F♯ (1)

Why it sounds like that

F♯ diminished 7th is built from the intervals 1, ♭3, ♭5, and ♭♭7 — a stack of three minor 3rds. The diminished 5th between F♯ and C gives the chord its unstable, tense quality. Compare it with F♯ minor 7th flat 5th, which raises the seventh from E♭ to E.

What goes wrong with F♯ diminished 7th?

  • Letting the index finger flatten and mute the 1st string.
  • Pressing too hard with the pinky, causing the 3rd string to buzz.
  • Failing to keep the middle finger perpendicular to the fretboard.

When to use it

F♯ diminished 7th often appears as a passing chord in jazz and classical music. It can resolve to F♯ minor 7th flat 5th or A♭ major. F♯ diminished 7th suits dramatic transitions and chromatic bass lines.

Changing to and from F♯ diminished 7th

  • Sliding the shape up one fret to the 2nd fret gives G diminished 7th.
  • Sliding the shape up two frets to the 3rd fret gives A♭ diminished 7th.

Which voicing to use

The 1st fret position keeps F♯ as the lowest note, giving a clear root-position sound. The F♯dim7/A inversion places A in the bass, creating a darker, less stable voicing. Choose the root position for foundational bass lines and inversions for smoother voice leading.

Other F♯ chords

Common questions

How is F♯ diminished 7th written?

F♯ diminished 7th is written as F♯°7 or F♯dim7. The ASCII root is F#, so you can type F#dim7. It is also spelled G♭ in enharmonic notation for the same sounding root.

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

F♯ diminished 7th has a double-flatted seventh (E♭), while F♯ minor 7th flat 5th has a minor seventh (E). The diminished 7th chord is more dissonant and symmetrical.

Why does F♯ diminished 7th sound so tense?

F♯ diminished 7th contains two diminished 5th intervals: F♯–C and A–E♭. These tritones create a strong pull toward resolution.