Augmented sixth chords

Definition

Augmented sixth chords are chromatic chords that typically resolve to the dominant chord and create a strong sense of tension before resolution. They are formed by taking the interval of an augmented sixth between the bass note and the tonic note of the key, often including a flattened sixth scale degree, which enhances their distinctive sound. These chords can be used for chromatic modulation, facilitating smooth transitions between keys, as well as enharmonic modulation, where they can be reinterpreted to serve different harmonic functions.

5 Must Know Facts For Your Next Test

1. Augmented sixth chords come in three main types: Italian, French, and German, each with distinct intervals and voicing.
2. These chords often include both the tonic and flattened sixth scale degree of the key, creating an augmented sixth interval that resolves outward to an octave.
3. In chromatic modulation, augmented sixth chords can facilitate a seamless transition to closely related keys by preparing the listener for a change in tonal center.
4. When used in enharmonic modulation, these chords can be reinterpreted to serve as different functional harmonies, allowing for creative and surprising shifts in harmony.
5. The use of augmented sixth chords adds richness and complexity to harmonic progressions, enhancing emotional expression in music.

Review Questions

• How do augmented sixth chords create tension that resolves effectively to the dominant chord?
  • Augmented sixth chords create tension by building an interval of an augmented sixth between their lowest note and the tonic note of the key. This tension is heightened because the notes in the chord are positioned to resolve outward to an octave as they move towards the dominant chord. The resulting pull towards the dominant creates a strong expectation for resolution, making it a powerful tool in harmonic progressions.
• Discuss how augmented sixth chords facilitate chromatic modulation between keys.
  • Augmented sixth chords facilitate chromatic modulation by providing a smooth transition between closely related keys. Since these chords inherently contain chromatic notes that do not belong to the original key, they can pivot to introduce new tonalities without abrupt changes. By resolving to a dominant chord in the new key, they effectively bridge the gap between two tonal centers, allowing composers to explore new harmonic territories.
• Evaluate the role of augmented sixth chords in enharmonic modulation and how they can change harmonic interpretation.
  • In enharmonic modulation, augmented sixth chords can be reinterpreted to assume different functional roles within a progression. This is possible because certain notes within these chords may serve dual purposes depending on their context. For example, an Italian augmented sixth can transform into a dominant seventh chord when viewed from another tonal perspective. This flexibility not only enriches harmonic language but also introduces surprising twists in musical narratives, allowing composers to explore complex emotional landscapes.

Related terms

Diatonic Harmony: Harmony that is built using only the notes of a given scale or key, often forming the basis for tonal music.

Secondary Dominant: A dominant chord that resolves to a chord other than the tonic, often used to create tension and drive towards a particular resolution in a progression.

Neapolitan Chord: A major chord built on the flattened second scale degree, typically used in first inversion and often functions as a predominant chord leading to the dominant.