Half-diminished seventh chord (ø7, dm, or diminished-minor)

Definition

A half-diminished seventh chord, often notated as ø7, is a four-note chord consisting of a root, a minor third, a diminished fifth, and a minor seventh. This chord has a unique sound that provides tension and is often used in various harmonic contexts, particularly in jazz and classical music. Its structure gives it distinct characteristics that help it function effectively in progressions, often leading to resolution or acting as a passing chord.

5 Must Know Facts For Your Next Test

1. The half-diminished seventh chord is built on the seventh scale degree in the harmonic minor scale and is commonly found in jazz progressions.
2. It functions as a ii°7 chord in minor keys, leading to the V chord in various harmonic contexts.
3. When analyzed in terms of intervals, this chord can be represented as 1, b3, b5, and b7.
4. The half-diminished seventh chord can resolve to major or minor chords, providing smooth transitions within a progression.
5. In Roman numeral analysis, this chord is typically represented as viiø7 when functioning within a minor key.

Review Questions

• How does the half-diminished seventh chord function within minor key progressions?
  • The half-diminished seventh chord primarily functions as the ii°7 chord in minor keys. This means it often leads to the dominant V chord, creating tension that resolves nicely when progressing to the tonic. The presence of this chord enhances harmonic movement and adds depth to musical passages.
• Compare and contrast the half-diminished seventh chord with the diminished seventh chord regarding their structures and uses.
  • While both chords share some common notes, the half-diminished seventh chord has a minor seventh instead of a diminished seventh found in the diminished seventh chord. This difference gives the half-diminished seventh its unique tension without being as unstable as the diminished seventh. As a result, while both chords can resolve to similar destinations, the half-diminished is often used more for smooth transitions in jazz contexts.
• Evaluate the significance of the half-diminished seventh chord's tritone interval in creating tension within musical compositions.
  • The tritone interval present in the half-diminished seventh chord plays a crucial role in establishing tension. This dissonant quality makes it an effective tool for composers seeking to create emotional depth or anticipation in their works. The resolution of this tension is what often drives musical narratives forward, making the half-diminished seventh chord essential in various genres such as jazz and classical music.

Related terms

Diminished seventh chord:

A diminished seventh chord is made up of a root, a minor third, a diminished fifth, and a diminished seventh, creating a tense and unstable sound.

Major seventh chord: A major seventh chord consists of a root, major third, perfect fifth, and major seventh, providing a stable and consonant sound often used in jazz and pop music.

Tritone:

A tritone is an interval spanning three whole tones, which is crucial in the construction of both diminished and half-diminished chords, contributing to their dissonant quality.