F♯dim7
F# Diminished 7th — perfectly symmetrical stacked minor thirds — the ultimate passing chord, able to resolve almost anywhere.
The keys
F♯ – A – C – E♭
What's inside F♯dim7
| Note | Interval from root | Degree |
|---|---|---|
| F♯ | Root | 1 |
| A | Minor 3rd | b3 |
| C | Diminished 5th | b5 |
| E♭ | Diminished 7th | bb7 |
Inversions
| Position | Keys (low → high) |
|---|---|
| Root position | G♭4 – A4 – C5 – E♭5 |
| 1st inversion | A4 – C5 – E♭5 – G♭5 |
| 2nd inversion | C5 – E♭5 – G♭5 – A5 |
| 3rd inversion | E♭5 – G♭5 – A5 – C6 |
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) | G♭2 – E♭3 |
| Right (colour) | A4 – C5 |
Where F♯dim7 lives
As the ii chord
F♯dim7 → B7 → Emaj7
Minor-family sevenths live on the ii — this is the move they were born for.
Stepwise colour
G♭ → F♯dim7 → A♭m7
Used as a passing colour between neighbouring chords.
Put F♯dim7 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 →