The German augmented sixth chord differs from the Italian augmented sixth chord primarily because:
AThe German sixth resolves to the dominant seventh chord rather than the tonic 6/4
BThe German sixth contains an additional chromatic pitch — a minor third above the bass — giving it four distinct pitches compared to the Italian sixth's three
CThe German sixth's augmented sixth interval contracts inward to a unison rather than expanding outward to an octave
DThe German sixth is used exclusively in minor keys, while the Italian sixth appears only in major keys
All three augmented sixth chord types share the defining feature: a chromatic bass pitch (typically the lowered sixth scale degree) and a raised fourth scale degree forming an augmented sixth interval that expands to an octave. The Italian sixth has only three distinct pitches: the bass, the tonic above it, and the raised fourth. The French sixth adds the second scale degree (#4 above bass). The German sixth adds a minor third above the bass (the lowered third scale degree), producing four pitches — the same as a dominant seventh chord enharmonically. Each variant's extra chromatic pitch must resolve correctly.
Question 2 Multiple Choice
In C major, an augmented sixth chord has Ab in the bass and F# in an upper voice — the augmented sixth interval. Where do these two voices move when resolving to the tonic 6/4?
ABoth voices move upward — Ab ascends to A♮ and F# ascends to G
BBoth voices converge on G by contrary stepwise motion — Ab descends a half step to G and F# ascends a half step to G — the augmented sixth expanding outward to a perfect octave
CAb moves up to A♮ (scale degree 6) while F# resolves down to E (scale degree 3)
DThe two outer voices hold while the inner voices resolve
The augmented sixth interval resolves by contrary outward motion: the lower voice (Ab, ♭6̂) descends by half step to G (5̂), and the upper voice (F#, ♯4̂) ascends by half step to G (5̂). Both voices land on the same pitch class — the dominant scale degree — creating a perfect octave. This outward expansion from the dissonant augmented sixth (enharmonically a minor seventh's width) to a consonant octave on the dominant is the defining voice-leading gesture of all augmented sixth chords, and the source of their characteristic forward drive.
Question 3 True / False
The augmented sixth interval in augmented sixth chords expands outward to a perfect octave when resolving to the tonic 6/4 chord.
TTrue
FFalse
Answer: True
This outward expansion is the defining voice-leading feature of the entire augmented sixth family. The ♭6̂ in the bass moves down by half step to 5̂; the ♯4̂ in an upper voice moves up by half step to 5̂. Both arrive on the dominant scale degree — the same pitch class — creating a perfect octave. This contrary half-step motion from the two chromatic notes is what gives these chords their characteristic urgency and forward pull toward the dominant.
Question 4 True / False
The Italian, French, and German augmented sixth chords most contain exactly the same pitches and differ mainly in how those pitches are distributed among the voices.
TTrue
FFalse
Answer: False
Each variant has a different number of distinct pitches and different chromatic content. The Italian sixth contains three pitches (♭6̂, 1̂, ♯4̂). The French sixth adds a fourth pitch: 2̂ (the supertonic). The German sixth also has four pitches but replaces 2̂ with ♭3̂ (the lowered mediant), making it enharmonically equivalent to a dominant seventh chord. These are genuinely different chords with different chromatic notes, not the same chord revoiced.
Question 5 Short Answer
What makes the augmented sixth interval such an effective dominant preparation? Explain why the outward resolution of its two defining voices to an octave creates strong forward motion.
Think about your answer, then reveal below.
Model answer: The augmented sixth interval is highly dissonant and unstable, creating strong expectation of resolution. Its two defining pitches — the lowered sixth scale degree below and the raised fourth scale degree above — point in opposite directions: each is a half step away from the dominant scale degree (5̂), which they approach by contrary motion. This half-step pull from both sides simultaneously is maximally directed: both voices move toward the same goal by the smallest possible melodic motion. The resulting octave on the dominant creates strong arrival energy that propels the music toward the tonic six-four and ultimately the authentic cadence. No other pre-dominant harmony has quite this double chromatic half-step pressure toward the dominant.
The key mechanism is dual half-step approach: both ♭6̂ and ♯4̂ are chromatically adjacent to 5̂ and move toward it by contrary motion. This is different from diatonic pre-dominant chords (IV, ii), which approach the dominant by whole step or larger intervals. The augmented sixth's chromatic compression creates what theorists sometimes call a 'gravitational pull' — both voices are one step away from their goal, and they arrive simultaneously from opposite directions.