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Half-Diminished Chord – Definition
A half-diminished chord is a four-note chord consisting of a root, a minor third, a diminished fifth, and a minor seventh. It is commonly written as m7♭5 or with the ø symbol.
What is a Half-Diminished Chord?
A half-diminished chord has the interval structure 1 – ♭3 – ♭5 – ♭7. It differs from a minor seventh chord by having a flattened fifth instead of a perfect fifth.
In tonal harmony, the half-diminished chord most commonly functions as the ii chord in a minor ii–V–i progression. For example, in A minor, the chord is Bm7♭5 (B–D–F–A), which naturally leads to E7 before resolving to Am.
Half-diminished chords are frequently found in jazz, classical music, film scores, and more sophisticated pop harmony because they create a strong sense of tension and forward movement.
How is a Half-Diminished Chord used in piano playing?
Pianists use half-diminished chords to add harmonic color and create smooth voice leading between chords. They are especially common in jazz accompaniment, ballads, and advanced chord progressions.
Learning to recognize and play half-diminished chords helps pianists understand functional harmony and perform richer chord progressions with greater confidence.