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Augmented sixth chords are a distinctive harmonic device in classical music, known for their dramatic and expressive qualities. These chords, characterized by an augmented sixth interval, often serve as powerful pre-dominant chords that create tension and resolution within a composition.
Understanding Augmented Sixth Chords
An augmented sixth chord typically consists of a root, an augmented sixth interval above the bass note, and often includes a perfect fifth or other chord tones. The most common types are the Italian, French, and German augmented sixth chords, each with unique intervallic structures and functions.
The Italian Augmented Sixth
The Italian augmented sixth (It+6) includes the notes ♯6 and ♭3 relative to the key. It resolves outward to the dominant, creating a strong pull towards the tonic. Its typical structure involves the notes ♯6 and ♭3 in the same chord, often with a root that forms an augmented sixth interval.
The French Augmented Sixth
The French augmented sixth (Fr+6) adds a second (or ♯4) to the Italian structure, creating a richer chord. It contains the notes ♯6, ♭3, and 2. This chord often includes a perfect octave or fifth above the bass and resolves to the dominant with a distinctive voice-leading.
The German Augmented Sixth
The German augmented sixth (Ger+6) extends the Italian by incorporating a ♭7 or subdominant note, making it a more complex chord. It features the notes ♯6, ♭3, and ♭7. Its resolution often involves a smooth voice-leading into the dominant, frequently passing through the tonic.
Common Patterns in Classical Music
Augmented sixth chords appear in various harmonic contexts within classical music, often serving as pivotal points in modulation, tension buildup, or expressive climax. Recognizing their patterns helps in analyzing and understanding the harmonic language of composers like Beethoven, Wagner, and Mozart.
Pattern 1: Resolution to the Dominant
The most frequent pattern involves the augmented sixth chord resolving outward to the dominant chord. This resolution creates a strong pull towards the tonic, emphasizing the harmonic tension and release. For example, in Beethoven’s works, the Italian augmented sixth often resolves to V, establishing a sense of closure.
Pattern 2: Modulation via Augmented Sixth
Composers frequently use augmented sixth chords to pivot to a new key. By resolving to the dominant of the new key, they facilitate smooth modulation. The German augmented sixth is especially effective in this role due to its complex structure and rich voice-leading.
Pattern 3: Chromaticism and Color
Augmented sixth chords often introduce chromaticism, adding color and emotional intensity. French and German augmented sixths, with their additional tones, provide more colorful harmonic textures. These chords are frequently used in Romantic-era compositions to heighten expressive qualities.
Examples in Classical Repertoire
Many famous compositions feature augmented sixth chords, illustrating their versatile roles. From Mozart’s early works to Wagner’s late operas, these chords enrich harmonic language and contribute to dramatic storytelling.
Beethoven’s Fifth Symphony
In Beethoven’s Fifth Symphony, augmented sixth chords are used to build tension before key changes, especially in the development sections. Their resolution creates a sense of triumph and resolution.
Mozart’s Piano Concertos
In Mozart’s piano concertos, augmented sixth chords often serve as transitional devices, seamlessly connecting different sections and keys with their distinctive sound.
Wagner’s Leitmotifs
Wagner employed augmented sixth chords extensively in his operatic works to heighten emotional impact and to facilitate complex modulations, contributing to the grandeur of his musical dramas.
Conclusion
Understanding the common patterns of augmented sixth chords enhances both the analysis and composition of classical music. Their unique ability to create tension and facilitate modulation makes them a vital element in the harmonic vocabulary of Western music tradition.