A German sixth chord is the chord built as a stack of the diminished third, major third and minor third, with the chord root on the raised fourth scale degree. It is easiest to recognize it as the diminished seventh flat three chord on the raised fourth scale degree. This way, we can easily recognize it in a score using the standard procedure for recognizing chords i.e. after we put its notes in the form of stacked thirds. This is shown in the next figure which shows the German sixth chord in the C major key.
Figure: The German sixth chord in the C major key annotated with the improper chord annotation
Unfortunately, diminished seventh flat three chord does not exist. 3 must not appear in altered tones of a chord (this was mentioned in chapter Altered, added and omitted tones). The only possible solution is to change the spelling of a chord. The next figure shows the German sixth chord in the C major key and in the position in which it appears most often. If we change the spelling from F# to Gb, we can write enh Ab7. “enh” tell us that the used annotation is only enharmonically equivalent to the chord as it is written in the score.
Figure: The German sixth chord in the C major key
In the C minor key, the harmony annotation would be c: enh VI7 and the chord annotation would be the same.
The resulting annotations are quite long and inconvenient. In the next chapter, we shall learn the harmony annotation for the German chord which is simple. However, there is no simple chord annotation for it.
The harmony annotation for the German sixth chord is Gr+6 no matter of a position in which it occurs. The next figure shows an example of the annotated German sixth chord in the position where it appears most often.
Figure: Annotating the German sixth chord
The German sixth chord is the same in a major key and its parallel minor key, thus having the same note names, chord notations and harmony annotations. This is illustrated in the next figure.
Figure: The German sixth chord in the C major key and its parallel C minor key
We see that if the current key is a minor key, the German sixth chord needs only one altered scale degree, the raised fourth scale degree. However, if the current key is a major key, the German sixth chord needs three altered scale degrees: the raised fourth scale degree, the lowered sixth scale degree and the lowered third scale degree. This is the reason why the German sixth chord appears more often in music written in minor keys.
The German sixth chord most often resolves to a chord with the root on the dominant (the fifth scale degree). The raised fourth scale degree resolves up to the fifth scale degree while the sixth scale degree resolves down to the fifth scale degree. This is illustrated in the next figure.
Figure: Resolving the German sixth chord in the C minor key
The next figure shows the beginning of Chopin’s Nocturne No. 20 in C# minor, op. posth. It contains an example of the German sixth chord. It resolves to a chord with the root on the dominant.
Figure: The beginning of Chopin’s Nocturne No. 20 in C# minor, op. posth.
The next figure shows the beginning of Beethoven’s Piano Sonata No. 14 in C# minor Op. 27 No. 2, third movement. It contains an example of the German sixth chord. It resolves to a chord with the root on the dominant.