--- title: "Augmented Sixth Chords: Italian, French and German Types" dek: "Italian, French and German sixth chords: how each type is built, how they resolve to V, and their use in enharmonic modulation." topic: harmony tags: [augmented sixth, chromatic harmony, modulation] date: 2026-10-04 author: Yunus Emre Vurgun level: advanced related: [functional-harmony, modulation-strategies, voice-leading-in-four-parts] faq: - q: What is an augmented sixth chord? a: It is a chromatic predominant built on the lowered sixth degree, containing an augmented sixth interval that expands outward to the octave of the dominant. In C major or minor the core notes are A flat and F sharp resolving to G and G. - q: How do Italian, French and German sixths differ? a: All three share the A flat to F sharp core in C. The Italian adds the tonic note (C), the French adds the second degree (D), and the German adds the minor third above the bass (E flat), making it sound like a dominant seventh in need of careful resolution. - q: Why does the German sixth need special voice leading? a: Resolving a German sixth directly to V creates parallel fifths between the lowered sixth degree and the third of the chord. The standard fix routes the resolution through a cadential six-four, which staggers the motion and removes the parallels. - q: Can augmented sixths modulate to distant keys? a: Yes. The German sixth sounds identical to a dominant seventh chord, so it can be reinterpreted as V7 of a flat-side key. Beethoven and Schubert used this enharmonic pivot to reach Neapolitan-side regions smoothly. --- Some chords exist for a single gesture: two voices stretching outward to an octave. The augmented sixth family turns that gesture into three distinct sonorities, each with its own color, its own resolution habits, and its own role in reaching the dominant with maximum pressure. ## The shared core Every augmented sixth chord in C major or C minor is built above A flat in the bass with F sharp somewhere above it. The interval from A flat to F sharp spans an augmented sixth, and both notes are tendency tones: A flat falls to G, F sharp rises to G. The chord exists to make that double pull audible. [keys]Ab3+F#4 G3+G4[/keys] The resolution above is the whole device in miniature. Two notes squeeze outward to an octave on the dominant pitch. Everything else in the three types is completion: which additional notes fill out the sonority and what color they lend. The chord functions as a predominant, sitting where the subdominant or supertonic would sit and driving toward V. Its bass, the lowered sixth degree, descends to the dominant by semitone, giving the progression a chromatic weight diatonic predominants cannot match. In [functional harmony](/articles/functional-harmony/) terms, augmented sixths are the most directional predominants available. ## Italian, French, and German The three national types differ by one note each. In C, with A flat in the bass and F sharp above: **Italian sixth (It+6).** Adds the tonic note C. The complete sonority is A flat, C, F sharp, usually with C doubled in four voices. Lean and urgent, it is the earliest type historically and the most transparent in texture. **French sixth (Fr+6).** Adds scale degree 2, D. The sonority A flat, C, D, F sharp contains two tritones and sounds appropriately tense. Whole-tone fragments hide inside it, which later composers noticed and exploited. **German sixth (Ger+6).** Adds E flat, the minor third above the bass. The stack A flat, C, E flat, F sharp sounds exactly like a dominant seventh chord (A flat 7), which creates both its richness and its voice-leading problem. | Type | Notes in C | Character | | --- | --- | --- | | Italian | A flat, C, F sharp | spare, vocal, early | | French | A flat, C, D, F sharp | brilliant, tense, coloristic | | German | A flat, C, E flat, F sharp | full, Wagnerian, pivot-ready | Hear the Italian move to the dominant, then the French with its extra edge. [keys]Ab3+C4+F#4 G3+B3+D4[/keys] [keys]Ab3+C4+D4+F#4 G3+B3+D4[/keys] The labels are conventional rather than geographical. No committee of Italians approved the Italian sixth. Theorists attached the names in the nineteenth century, and the terms stuck because the three sonorities genuinely differ in weight and use. ## Resolving each type The Italian sixth resolves directly to V with no complications. Double the tonic note, move the augmented sixth outward to the dominant octave, and let the doubled note step to the leading tone or hold as a common tone. Student exercises should begin here. The French sixth also resolves directly. Its four distinct notes fit four voices without doubling decisions, and each voice has a clear destination: A flat down to G, F sharp up to G, C down to B, D down to C or up by step depending on context. The D to C motion fills the resolution with stepwise descent. The German sixth is the problem child. Its E flat wants to fall to D (the fifth of V) while its A flat falls to G, and those two falling voices form consecutive fifths with each other. Three solutions exist. The standard one interposes a cadential six-four between Ger+6 and V, so the E flat descends to D against a stationary G bass and no parallels occur. Alternatives move the E flat up to E natural (creating a major V arrival with a doubled third) or resolve to I6/4 in deceptive contexts. Master the cadential six-four route first; the doubling and spacing rules behind it are the same ones in [four-part voice leading](/articles/voice-leading-in-four-parts/). In minor keys the German sixth coincides with an altered iv7 sonority, which tempts analysts to label it as such. The augmented-sixth reading is preferred whenever the F sharp behaves as a raised fourth resolving up, since the label then predicts the voice leading instead of merely cataloging the pitches. ## The enharmonic pivot Because the German sixth sounds identical to a dominant seventh, it modulates by reinterpretation. The Ger+6 of C (A flat, C, E flat, F sharp) respelled as A flat, C, E flat, G flat is the V7 of D flat major. One chord, two functions, and the music slips a semitone flatward without any audible seam. Schubert and Beethoven made this move famous. A development section heading toward flat regions will plant a sonority the ear takes for V7, then resolve it as an augmented sixth back toward the sharp side, or plant an augmented sixth and exit as V7 into the flat key. The listener hears smooth chromaticism; the analyst sees a hinge between distant tonal areas. The technique belongs to the larger craft of [modulation strategies](/articles/modulation-strategies/), where enharmonic pivots handle the longest distances. Notation gives the game away, which is why spelling matters. F sharp resolving up to G signals augmented sixth; G flat resolving down to F signals dominant seventh. Performers reading the part see the intended function in the accidental, and editors who normalize the spelling destroy the information. When writing the pivot yourself, spell for the resolution the chord actually takes. ## Where augmented sixths mislead people The commonest error is building the chord on the wrong bass note. The bass must be the lowered sixth degree (A flat in C), not the raised fourth. An F sharp bass with A flat above inverts the interval to a diminished third and the sonority loses its predominant bass motion. Check the bass first, always. A second mistake stacks the German sixth like a dominant seventh and resolves it as one while calling it augmented. If F sharp falls to F natural over a D flat resolution, the chord was V7 of D flat, not Ger+6 of C. Function follows the resolution, and the label must follow the function. Students also overuse the French sixth for its glitter without noticing its whole-tone implications. In strict common-practice style the French resolves like the others, but its two tritones give later composers whole-tone ideas that pull away from tonal syntax. Using it innocently in a Mozart-pastiche exercise sounds subtly wrong to a trained ear; the Italian sits more naturally in early styles. ## What to do with it Write the progression iv6 to It+6 to V to i in every minor key, keeping the bass stepwise throughout. The bass line (in A minor: D C B) teaches the hand the chromatic descent that carries the whole family. Then substitute the French and German types in the same frame and feel how the added notes change the weight. At the piano, practice the German sixth resolution both ways: through the cadential six-four and directly with the E flat rising. Listen for the parallel fifths in the forbidden version by playing the outer voices of A flat to G against E flat to D. Hearing the violation once teaches more than reading about it twice. Finish by finding the enharmonic pivot in Schubert: locate a passage where a dominant-seventh-shaped sonority resolves as an augmented sixth, or the reverse. Mark the respelled note and the two keys it joins. That single hinge, understood deeply, unlocks the flat-side modulations of the entire Romantic repertoire.