Guitar Chord Fdim: Structure, Notes and Theory

Fdim — a chord built on the note “F” with a tense, sharp tone that adds drama. Often used as a passing chord to boost expressiveness and create intrigue.

Formula and Structure of the Fdim Chord

Interval formula from the root note: 1 — b3 — b5. The chord consists of the following notes:

• F — unison and the main tonal anchor.
• Ab — minor third with a melancholic character and gentle lyricism.
• B — diminished fifth with tritone tension, best used cautiously in the bass.

Together, these notes form the harmonic foundation of the Fdim chord, defining its sound and role in the musical context.

Alternative Names for the Fdim Chord

This chord may appear under different names:

• F°

All variants refer to the same harmonic structure.

Using the Fdim Chord

Put the b5 in the middle or top register to avoid overloading the bass. Use as a link between diatonic chords or to create dramatic moments. In slow tempos, you can highlight its symmetrical structure.

Conclusion

Fdim is an expressive and versatile chord. Learn several fingerings, experiment with different positions and voice spacing, then try weaving it into your own playing — this will help you quickly find your unique tone.