Augmented 6th chords – German 6th

In a prior lesson, we learned about the Italian 6th chord. In this lesson we will look at the German 6th.

As an example, we will use the same piece as before – Mozart’s Piano Sonata No. 6, K. 284, Mvt. 3, Variation VII. We had analyzed it thus far:

We analyzed all the chords we knew and now have an analysis for the chord in m. 3 – the Italian 6th chord.

Now, let’s look at the chord in m. 6.

Mozart, Piano Sonata No. 6, Mvt. 3, Variation VII, m. 6

A modulation occurred in measure 5; the piece goes from the key of D minor to A minor. The key of a minor is confirmed by the cadence in measures 7-8 — a perfect authentic cadence in the key of A minor.

The chord in measure 6 can be reduced to the following:

This chord can be enharmonically spelled as an F7 (F-A-C-Eb). However, if it were an F7, it would resolve down a fifth to Bb, as shown below:

Instead, this chord resolves to a cadential64 to V in the key of A minor (see reduction below).

Therefore, it is not functioning as a dominant 7th (F7) chord.

The chord contains the following intervals — M3, P5 and Augmented 6th above the bass.

Since it contains the interval of an augmented 6, it is a form of an augmented 6th chord. Specifically, this chord is a German 6 and, since it is built on the note a half-step above dominant, it resolves to a dominant chord. The interval of the augmented 6th expands to the octave of scale degree 5 and the other notes go to the nearest chord tone.

Therefore, we analyze this chord as a German 6 (Ger6) in the analysis of the Mozart Variation, as shown below.

Jazz notation for the German 6

Since the German 6 is enharmonic to a complete V7 chord, in jazz notation these chords are just marked as a dominant 7 chord.

The example below shows the Mozart Variation analyzed with both roman numeral analysis and jazz chords.

Notes on Voice Leading of German 6th

It is important to note that when resolving the German 6 built on the note a half step above dominant directly to a V chord parallel 5ths will most likely occur when taking all the notes to the nearest chord tone.

There is no way to avoid this problem since the perfect 5th interval will always be present above the bass.

To avoid the parallel 5ths, resolve the German 6 to either a cadential 64 or another augmented 6 chord before going to the V chord. By doing this, the resolution of the 5th is staggered and so no parallel technically occur.

Summary

In this lesson we learned a bit about the German augmented 6th chord.

Augmented sixth chords are altered chords that contain the interval of an augmented sixth.

The most common augmented sixth chords’ bass note is a half-step above the dominant. Above this bass note, they also contain the note a half-step below the dominant – creating the interval of the augmented 6th.

The German 6th also contains the intervals of a Major 3 and the Perfect 5.

The German 6th chord will sound like a complete V7 chord.

The interval of the augmented 6th usually resolves out to an octave. These chords will resolve to the V or V7 chord (or a cadential 64 chord).

In jazz notation, the Italian and German 6 chords are marked as dominant 7 chords.