Fdim
F Diminished — tense and unstable by design — built from stacked minor thirds, it begs to resolve.
The keys
F – A♭ – C♭
What's inside Fdim
| Note | Interval from root | Degree |
|---|---|---|
| F | Root | 1 |
| A♭ | Minor 3rd | b3 |
| C♭ | Diminished 5th | b5 |
Inversions
| Position | Keys (low → high) |
|---|---|
| Root position | F4 – A♭4 – B4 |
| 1st inversion | A♭4 – B4 – F5 |
| 2nd inversion | B4 – F5 – A♭5 |
A working voicing
Split the chord between two hands the way working players do — a solid shell low down, the colour tones up top:
| Hand | Keys |
|---|---|
| Left (shell) | F2 – F3 |
| Right (colour) | A♭4 – B4 |
Where Fdim lives
As the I chord
Fdim → B♭ → C → Fdim
The classic I–IV–V–I motion with this chord as home.
In a ii–V–I
Gm7 → C7 → Fdim
The strongest cadence in harmony, resolving onto this chord.
Put Fdim under your fingers
Hear every voicing, see the keys light up, and drill it in the interactive Chord & Voicing Lab.
Open the Chord & Voicing Lab →