Triads
F diminished chord
Tense and unstable — it usually wants to resolve up by a half step.
Fdim is the vii° chord in F♯ major. In minor keys: ii° in E♭ minor.
- Notes
- FA♭C♭
- Formula
- 1♭3♭5
- Built from
- root · minor 3rd · diminished 5th
How to play Fdim
About the F diminished chord
Playing it
On guitar, Fdim has an open-position shape, xx3101, using three fingers alongside the open strings. Don’t strum the low E and A strings.
On piano, Fdim has one black key (A♭) and two white keys.
On ukulele the usual Fdim shape is 4542, using four fingers.
Related chords
Move a single note and Fdim becomes a different chord: raise C♭ to C for Fm, add E♭ for Fm7♭5 and add E𝄫 for Fdim7.
Where you’ll hear it
Notice the C♭ in Fdim (F A♭ C♭): each note of the chord takes its own letter (F–A–C), so the diminished 5th has to be written C♭ rather than B — the same key on a piano, spelled to fit the chord.
