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F diminished 7th chord on bass (Fdim7)
Also called or written Fdim7 or F°7
F diminished 7th contains F, A♭, C♭, and E♭♭. Its open position uses the open D string, creating a ringing, resonant sound.
How it is built
Formula 1, ♭3, ♭5, ♭♭7
- Root positionF–A♭–C♭–E♭♭Fdim71-2-0-1
- First inversionA♭–C♭–E♭♭–FFdim7/A♭4-5-3-4
- Second inversionC♭–E♭♭–F–A♭Fdim7/C♭7-8-6-7
- Third inversionE♭♭–F–A♭–C♭Fdim7/E♭♭10-11-9-10
How do you play an F diminished 7th chord on bass?
F diminished 7th is played in open position as 1 2 0 1: index finger on the E string at fret 1, ring finger on the A string at fret 2 and middle finger on the G string at fret 1. The D string rings open.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 1 | 1 | F (1) |
| 3 (A) | 2 | 3 | C♭ (♭5) |
| 2 (D) | open | — | E♭♭ (6) |
| 1 (G) | 1 | 2 | A♭ (♭3) |
AdvancedThe open D string must ring clearly while the surrounding fingers fret nearby notes, requiring precise finger placement.
12th fret
F diminished 7th is played at the 12th fret as 13 14 12 13: middle finger on the E string at fret 13, pinky finger on the A string at fret 14, index finger on the D string at fret 12 and ring finger on the G string at fret 13.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 13 | 2 | F (1) |
| 3 (A) | 14 | 4 | C♭ (♭5) |
| 2 (D) | 12 | 1 | E♭♭ (6) |
| 1 (G) | 13 | 3 | A♭ (♭3) |
Fdim7/A♭ inversion
F diminished 7th is played at the 3rd fret as 4 5 3 4: middle finger on the E string at fret 4, pinky finger on the A string at fret 5, index finger on the D string at fret 3 and ring finger on the G string at fret 4.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 4 | 2 | A♭ (♭3) |
| 3 (A) | 5 | 4 | E♭♭ (6) |
| 2 (D) | 3 | 1 | F (1) |
| 1 (G) | 4 | 3 | C♭ (♭5) |
Fdim7/C♭ inversion
F diminished 7th is played at the 6th fret as 7 8 6 7: middle finger on the E string at fret 7, pinky finger on the A string at fret 8, index finger on the D string at fret 6 and ring finger on the G string at fret 7.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 7 | 2 | C♭ (♭5) |
| 3 (A) | 8 | 4 | F (1) |
| 2 (D) | 6 | 1 | A♭ (♭3) |
| 1 (G) | 7 | 3 | E♭♭ (6) |
Fdim7/E♭♭ inversion
F diminished 7th is played at the 9th fret as 10 11 9 10: middle finger on the E string at fret 10, pinky finger on the A string at fret 11, index finger on the D string at fret 9 and ring finger on the G string at fret 10.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 10 | 2 | E♭♭ (6) |
| 3 (A) | 11 | 4 | A♭ (♭3) |
| 2 (D) | 9 | 1 | C♭ (♭5) |
| 1 (G) | 10 | 3 | F (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 touch the open D string, muting it.
- Pressing too hard with the ring finger, causing the 3rd string to buzz.
- Failing to keep the middle finger arched, resulting in a muted 1st string.
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 G major. F diminished 7th suits dramatic transitions and chromatic bass lines.
Changing to and from F diminished 7th
- Sliding the shape down two frets to the 10th fret gives E♭ diminished 7th.
Which voicing to use
The open position keeps F as the lowest note, giving a clear root-position sound. The Fdim7/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 Fdim7.
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.