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F#dim(Diminished Chord)

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

Notes
F# – A – C
Intervals (semitones)
0 – 3 – 6
Type
Triad

🎹 F#dim on Piano

Press highlighted keys simultaneously to play the F#dim chord.

R
F#(Root (R))
2
A(Minor 3rd (♭3))
3
C(Tritone (♭5))

🎸 F#dim on Guitar

The F#dim chord uses notes F#, A, C. 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)3A
5thTritone (♭5)6C

About the F# Diminished Chord

The F#dim chord (F# Diminished) consists of 3 notes: F#, A, C. 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#, A, C.

Playing F#dim on Piano

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

Common Chord Progressions Using F#dim

  • I–IV–V: F#dim – Bdim – C#dim (blues and rock)
  • I–V–vi–IV: F#dim – C# – D#m – B (pop staple)
  • I–vi–IV–V: F#dim – D#m – B – C# (50s progression)

The F#dim Chord in Context

As a diminished chord, F#dim 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 B major — making it one of the most important chords across all of Western music.

Other F# Chords

F#
Major
F#m
Minor
F#7
Dominant 7th
F#maj7
Major 7th
F#m7
Minor 7th
F#aug
Augmented

Diminished Chord in All 12 Keys

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

FAQ

F#dim Chord — Frequently Asked Questions

What notes are in the F#dim chord?
The F# Diminished chord contains: F#, A, C. These notes are derived by applying the diminished interval formula (0–3–6 semitones) to the root note F#.
What is the F#dim chord used for?
Built from two stacked minor thirds. Creates maximum tension and instability. The F#dim 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 F#dim on piano?
On piano, play F#, A, C simultaneously. In root position, F# is the lowest note. Inversions move the bass note up — first inversion has A lowest, second inversion has C lowest.
How many notes are in a diminished chord?
A diminished chord has 3 notes: F#, A, C (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#–A–C#) uses a minor third (3 semitones), giving it a darker, emotional sound.
What key does F#dim belong to?
F#dim 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 B major.
Can I play F#dim on ukulele?
Yes. The ukulele uses GCEA tuning with 4 strings. The F#dim chord notes (F#, A, C) 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 F#dim?
In the key of F# major, F#dim pairs naturally with B major (IV), C# major (V), and D#m (vi). The classic I–IV–V (F#dim–B–C#) is the foundation of blues, country, and rock.
What is a chord inversion of F#dim?
An inversion places a non-root note in the bass. F#dim root position: F# in bass. First inversion: A in bass. Second inversion: C 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 F#dim: start on F#, add 3 semitones, then 6 semitones. Practicing this across all 12 roots builds instant recognition of any diminished chord.