The short version
- Fdim is F diminished. Its notes are F, A♭ and C♭ (sounds as B) (formula 1 – ♭3 – ♭5).
- Easiest way to play it: a barre on the 1st fret, frets 1 2 3 1 x x from low E to high E (x = don’t play).
- It sounds tense, spooky, unresolved. Use it as a passing chord that leads up a semitone (Bdim to C), or as the vii° of a major key.
- Fdim turns up in 2 keys: F♯ major (as the vii°) and E♭ minor (as the ii°).
- Can’t barre yet? Capo 1 and play an open Edim shape.
How to play Fdim on guitar, step by step
Start with the shape marked “Start here” above: the barre chord, root on the 6th string (1st fret).
- Lay your index finger flat across fret 1, from the 6th (low E) string to the 3rd (G) string. That’s the barre: press near the fret wire and roll the finger slightly onto its side.
- Put your middle finger on fret 2 of the 5th (A) string.
- Put your ring finger on fret 3 of the 4th (D) string.
- Don’t play the B and high E strings: skip them, or touch them lightly with a spare finger so they can’t ring.
- Strum from the 6th (low E) string down, then press Strum on this page to check it sounds the same.
Once that’s comfy, try the other shape. Shape 2 is the movable shape, root on the 5th string (8th fret): x 8 9 10 9 x. Same chord, different spot on the neck, which helps when the next chord lives nearby.
No barre? No problem. Pop a capo on the 1st fret and play the open Edim shape: it comes out as Fdim. (Capo 3 with an open Ddim shape works too.) Barre chords take everyone a few weeks. Mine sounded like a kettle for a month.
Notes in the Fdim chord
Fdim is built from 3 notes. On guitar you’ll often play some of them twice, on different strings. That’s normal; the chord is still Fdim.
| Note | Interval | What it does |
|---|---|---|
| F | 1 root | Names the chord and anchors the bass. |
| A♭ | ♭3 minor third | Makes it minor (sad). |
| C♭ (sounds as B) | ♭5 diminished fifth | The tense, spooky bit. |
What Fdim sounds like, and when to use it
Two minor thirds stacked up. Tense and a little spooky: the chord that plays in old films when the villain twirls his moustache. Use it as a passing chord that leads up a semitone (Bdim to C), or as the vii° of a major key.
What key is Fdim in?
Fdim turns up in 2 keys: F♯ major (as the vii°) and E♭ minor (as the ii°). Tap a key to see the rest of its chords on the circle of fifths.
| Key | Numeral | Spelled as |
|---|---|---|
| F♯ major | vii° | Fdim |
| E♭ minor | ii° | Fdim |
Chords that go with Fdim
Here’s a progression to try: G♭ – B – Fdim – G♭ (I–IV–vii°–I), the diminished chord as the leading-tone chord, pulling up a semitone.
More progressions → Transpose it →
Using Fdim in a Suno prompt
Suno pays attention to chord names in a style prompt, at least some of the time. Put the progression in, keep the BPM, and let it fill in the rest. Then compare its guitar part with the shapes above.
Dark cabaret, 88 BPM, chord progression G♭ – B – Fdim – G♭, diminished passing chords, theatrical piano, creeping strings, mysterious and playful vocals
Fdim chord FAQ
What notes are in the Fdim chord?
Fdim has 3 notes: F (the root), A♭ (the minor third) and C♭ (sounds as B) (the diminished fifth). The chord formula is 1 – ♭3 – ♭5.
How do you play Fdim on guitar?
The medium way is barre chord, root on the 6th string (1st fret). Strings from low E to high E: 1 2 3 1 x x (x means don’t play that string). Lay your index finger flat across fret 1, from the 6th (low E) string to the 3rd (G) string. That’s the barre: press near the fret wire and roll the finger slightly onto its side. Put your middle finger on fret 2 of the 5th (A) string. Put your ring finger on fret 3 of the 4th (D) string. Don’t play the B and high E strings: skip them, or touch them lightly with a spare finger so they can’t ring.
What does the “dim” in Fdim mean?
It tells you the chord type: Fdim is F diminished. Two minor thirds stacked up. Tense and a little spooky: the chord that plays in old films when the villain twirls his moustache.
What key is Fdim in?
Fdim turns up in 2 keys: F♯ major (as the vii°) and E♭ minor (as the ii°). Major keys: F♯ major. Minor keys: E♭ minor.
What is the difference between Fdim and Fm?
Both have a minor third. Fm has a perfect fifth (C); Fdim drops it a semitone to C♭, which makes it tense and unstable.
How can I play Fdim without a barre?
Use a capo. Put it on the 1st fret and play the open Edim shape or Put it on the 3rd fret and play the open Ddim shape. It sounds as Fdim. You can also play just the top three or four strings of the barre shape.
Other diminished chords
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