Half-Diminished Seventh Chords

Definition

A half-diminished seventh chord is a four-note chord consisting of a root, a minor third, a diminished fifth, and a minor seventh. This chord is also known as a minor seventh flat five chord and often appears in jazz and classical music as a common substitution for dominant chords or within harmonic progressions. Its unique sound creates tension that typically resolves to a tonic or major chord.

5 Must Know Facts For Your Next Test

1. The half-diminished seventh chord can be notated as 'ø7' or 'm7♭5', indicating its minor seventh and diminished fifth characteristics.
2. This chord functions well as the ii chord in a minor key, often leading to the V7 chord before resolving to the i chord.
3. Half-diminished chords can add color and complexity to musical pieces, especially when used in modal interchange or jazz contexts.
4. The interval structure of a half-diminished seventh chord includes the minor third from the root to the third note and the minor seventh from the root to the fourth note.
5. The half-diminished seventh chord is often used in jazz standards and can be found in various genres due to its rich harmonic quality.

Review Questions

• How does the half-diminished seventh chord function within harmonic progressions?
  • The half-diminished seventh chord typically serves as the ii chord in a minor key, leading to the dominant seventh chord (V7) before resolving to the tonic (i). This movement creates a strong sense of tension and release, enhancing the harmonic flow. Its ability to substitute for dominant chords allows for greater variety in progressions, making it essential for composers and arrangers.
• Compare and contrast half-diminished seventh chords with diminished seventh chords, focusing on their structures and uses.
  • Half-diminished seventh chords consist of a root, minor third, diminished fifth, and minor seventh, while diminished seventh chords have a root, minor third, diminished fifth, and diminished seventh. The half-diminished chord tends to create tension that resolves more smoothly than its fully diminished counterpart. In practice, half-diminished chords are often used in more stable harmonic contexts compared to diminished sevenths that create greater instability.
• Evaluate the significance of half-diminished seventh chords in jazz harmony and how they contribute to overall musical expression.
  • Half-diminished seventh chords play a critical role in jazz harmony by providing rich harmonic textures and smooth voice leading. Their unique sound can add emotional depth to improvisations and compositions. Musicians often use them as substitutes for dominant chords or within complex progressions, allowing for greater creative expression. The versatility of half-diminished chords enables them to bridge different styles while enriching musical narratives through tension and resolution.

Related terms

Diminished Seventh Chord: A diminished seventh chord is similar to the half-diminished seventh but includes a diminished seventh rather than a minor seventh, resulting in a more unstable sound.

Dominant Seventh Chord:

A dominant seventh chord consists of a root, major third, perfect fifth, and minor seventh, commonly used in jazz and blues music to create tension that resolves to the tonic.

Chord Progression:

A sequence of chords played in succession, creating the harmonic foundation for melodies and compositions.