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Fdim(Diminished Chord)

Built from two stacked minor thirds. Creates maximum tension and instability.

Notes
F – G# – B
Intervals (semitones)
0 – 3 – 6
Type
Triad

🎹 Fdim on Piano

Press highlighted keys simultaneously to play the Fdim chord.

R
F(Root (R))
2
G#(Minor 3rd (♭3))
3
B(Tritone (♭5))

🎸 Fdim on Guitar

The Fdim chord uses notes F, G#, B. Build a voicing by finding these notes on any strings — root on the 6th string is a common starting point for barre chord shapes.

Interval Analysis

DegreeInterval NameSemitonesNote in F
RootRoot (R)0F
3rdMinor 3rd (♭3)3G#
5thTritone (♭5)6B

About the F Diminished Chord

The Fdim chord (F Diminished) consists of 3 notes: F, G#, B. Built from two stacked minor thirds. Creates maximum tension and instability.

To build any diminished chord, apply intervals of 0, 3, 6 semitones above the root. Starting from F: the notes land on F, G#, B.

Playing Fdim on Piano

Press F, G#, B simultaneously. In root position, F is lowest. First inversion places G# in the bass for a lighter sound; second inversion uses B as the bass note.

Common Chord Progressions Using Fdim

  • I–IV–V: Fdim – A#dim – Cdim (blues and rock)
  • I–V–vi–IV: Fdim – C – Dm – A# (pop staple)
  • I–vi–IV–V: Fdim – Dm – A# – C (50s progression)

The Fdim Chord in Context

As a diminished chord, Fdim is the tonic (I) in the key of F major. It also appears as the IV chord in C major, and as the V chord in A# major — making it one of the most important chords across all of Western music.

Other F Chords

F
Major
Fm
Minor
F7
Dominant 7th
Fmaj7
Major 7th
Fm7
Minor 7th
Faug
Augmented

Diminished Chord in All 12 Keys

CdimC#dimDdimD#dimEdimFdimF#dimGdimG#dimAdimA#dimBdim
🎹 Virtual Piano
Play Fdim on piano
🎸 Virtual Guitar
See on the fretboard
🎵 F Scale
Notes that fit Fdim
🎶 Songs
Find songs using Fdim

FAQ

Fdim Chord — Frequently Asked Questions

What notes are in the Fdim chord?
The F Diminished chord contains: F, G#, B. These notes are derived by applying the diminished interval formula (0–3–6 semitones) to the root note F.
What is the Fdim chord used for?
Built from two stacked minor thirds. Creates maximum tension and instability. The Fdim chord is used across pop, rock, jazz, and classical music. As the I chord in the key of F major, it functions as the most stable resting point in progressions.
How do you play Fdim on piano?
On piano, play F, G#, B simultaneously. In root position, F is the lowest note. Inversions move the bass note up — first inversion has G# lowest, second inversion has B lowest.
How many notes are in a diminished chord?
A diminished chord has 3 notes: F, G#, B (in F). It is a triad — the most fundamental chord type.
What is the difference between F major and F minor?
The F major chord (F–A–C) uses a major third (4 semitones), giving it a bright, happy sound. The F minor chord (F–G#–C) uses a minor third (3 semitones), giving it a darker, emotional sound.
What key does Fdim belong to?
Fdim naturally serves as the I chord in the key of F major. It also appears as IV in the key of C major, and as V in the key of A# major.
Can I play Fdim on ukulele?
Yes. The ukulele uses GCEA tuning with 4 strings. The Fdim chord notes (F, G#, B) can be fretted on a ukulele, though the shapes differ from guitar due to the 4-string layout and shorter scale.
What chords go well with Fdim?
In the key of F major, Fdim pairs naturally with A# major (IV), C major (V), and Dm (vi). The classic I–IV–V (Fdim–A#–C) is the foundation of blues, country, and rock.
What is a chord inversion of Fdim?
An inversion places a non-root note in the bass. Fdim root position: F in bass. First inversion: G# in bass. Second inversion: B in bass. Inversions create smoother bass line movement without changing the harmony.
How do I memorize the notes in a diminished chord?
Remember the formula: 0–3–6 semitones from root. For Fdim: start on F, add 3 semitones, then 6 semitones. Practicing this across all 12 roots builds instant recognition of any diminished chord.