Diminished chord - piano

The diminished chord is a triad composed of a root, a minor third and a diminished fifth. Notated dim or °, it creates strong harmonic tension, often used as a passing chord.

Intervals

Degree I♭III♭V
Interval RootMinor thirdDiminished fifth
Semitones 036

Formula 1 - ♭3 - ♭5

Theory

The diminished chord is built with two successive minor thirds (3 + 3 semitones). The diminished fifth (6 semitones) creates a characteristic dissonance. C diminished = C-E♭-G♭, D diminished = D-F-A♭. This chord is symmetrical: each inversion produces another diminished chord.

Examples

Example: Do Diminished

Diminished chord diagram on piano - Bass fret 999

Styles

Jazz Classique Blues Gospel Bossa Nova

Construction

Formula 1 - 3b - 5b: diminished fifth (tritone). Tension and instability.

How to play

Compact 3-4 string positions. Chromatic use (C - C#dim - Dm).

Learning

Practice in resolution context.

Triad inversions on piano

On piano, inversions are fundamental for creating smooth progressions and avoiding bass leaps.

The 2 possible inversions

  • 1st inversion (sixth chord): third in bass (3-5-1), noted I6. Creates melodic bass lines.
  • 2nd inversion (six-four chord): fifth in bass (5-1-3), noted I6/4. Used as cadential chord or bass pedal.

Mastering inversions is essential for keyboard harmony: they keep voices close and avoid large leaps between chords.