Augmented sixth chord

The augmented sixth (which is a minor seventh) is found mainly in two chords: the German sixth and the French sixth.

AbateFaria wrote:

The augmented sixth (which is a minor seventh) is found mainly in two chords: the German sixth and the French sixth.

ALTERED SIXTH CHORDS: ITALIAN, FRENCH, GERMAN AND ENHARMONIC GERMAN (SWISS)

http://websolci.altervista.org/attachments/article/14/Seste%20eccedenti-esempi.pdf

thanks guys, I would also like to ask you on which scale degrees the augmented sixths are found, I just read: on the II degree of the major mode or on the IV of the minor mode, does that seem correct to you? and is there a difference between a "simple" augmented sixth and the other augmented sixths? (German, Swiss, Italian and French) I don't know if I forgot one but the topic of sixths is still not clear to me

thanks for the help

Aspirante wrote:

ALTERED AUGMENTED SIXTH CHORDS: ITALIAN, FRENCH, GERMAN AND ENHARMONIC GERMAN (SWISS)

http://websolci.altervista.org/attachments/article/14/Seste%20eccedenti-esempi.pdf

i can't open the link

Let's say that it should be premised that these chords arise from contrapuntal movements; the first to use the Italian sixth with harmonic (rather than contrapuntal) awareness were Vivaldi and Caldara, the latter also using the German sixth, which was then widely used in the 1800s along with the French one.

The German sixth, for example, enharmonically coincides with a dominant seventh, making it very convenient for modulating; to know on which degree you are using it, you should analyze what comes before and after. It can certainly be followed by a V[46 35] or by another seventh chord, depending on where you want to go.

a typical procedure is the following, in D minor (from bass to treble):

Bb D G

Bb D F G# (GER)

Then V

A C F A

or

Bb D G

Bb D F G# (GER)

Bb D E G# (FRA)

Then V

If you analyze the harmonic successions, you might find answers, but one can certainly notice immediately (contrapuntally speaking) the chromatic movements of the parts. (see in the first example G G# A in the highest part).

The augmented sixth, as an interval, is located on the 6th degree. For example, in C minor, it is located on the Ab. The interval is therefore Ab-F# (augmented sixth).

On this augmented sixth interval, you can build several chords: German sixth (Ab-C-Eb-F#), French sixth (Ab-C-D-F#), Italian sixth (Ab-C-F#). They are all chords that precede a dominant (V or I46).

RedScharlach wrote:

They are all chords that precede a dominant (V or I46).

Having a German sixth followed directly by a V, there is a possibility of creating fifth parallelisms; in a stylistic reconstruction, it is better to use the double appoggiatura 46.

Frank wrote:

Let's just say that it should be premised that these chords arise from contrapuntal movements; the first to use the Italian sixth with harmonic (rather than contrapuntal) awareness were Vivaldi and Caldara, the latter also using the German one which, together with the French one, was widely used in the 1800s.

The German sixth, for example, enharmonically coincides with a dominant seventh, making it very convenient for modulating; to know on which degree you are using it, you should analyze what comes before and after. It can certainly be followed by a V[46 35] or by another seventh chord, depending on where you want to go.

A typical procedure is as follows, in D minor (from bass to treble):

Bb D G

Bb D F G# (GER)

Then V

A C F A

or alternatively

Bb D G

Bb D F G# (GER)

Bb D E G# (FRA)

Then V

If you analyze the harmonic successions, you might find answers, but one can certainly notice immediately (contrapuntally speaking) the chromatic movements of the parts. (see in the first example G G# A in the highest part).

Thanks!! So the German sixth enharmonically coincides with a dominant seventh! I didn't know that..

It is possible to build an augmented sixth chord on every degree of the scale and not just on the II of the major scale, right? Did I understand correctly?

Precisely for this reason I was writing 46, which corresponds to the double appoggiatura.

Gerardo wrote:

Having a German sixth followed directly by a V, there is the possibility of creating fifth parallelisms; in a stylistic reconstruction, it is better to use the 46 double appoggiatura.

Fox wrote:

Thank you!! so the German sixth coincides enharmonically with a dominant seventh! I didn't know..

Is it possible to build an augmented sixth chord on every degree of the scale and not just on the II of the major scale, right? Did I understand correctly?

No: as I was writing in the previous post, augmented sixth chords are built on the VI of the minor scale. In C minor on Ab (interval of 6E Ab-F#), in D minor on Bb (interval of 6E Bb-G#), and so on.

RedScharlach wrote:

No: as I was writing in the previous post, augmented sixth chords are built on the VI of the minor scale. In C minor on Ab (6E interval Ab-F#), in D minor on Bb (6E interval Bb-G#), and so on.

ah! thank you so much now I understand! so only on the VI degree of the minor scale

..sorry, it's just that my book says they are built on the II degree of the major mode or on the IV of the minor mode

RedScharlach wrote:

That is exactly why I was writing I46, which corresponds to the double appoggiatura.

Ah, one too many betrayed me

> (V or I46).

In any case, the double appoggiatura is indicated like this V[46 35] precisely because it is not I (functionally)… harpsichordists in the continuo use only 46 because they only read the interval relationships with the bass. In fact, you are on a V. I46 is indicated when one is on the first inversion, which is not the case of the double appoggiatura.

Fox wrote:

..sorry, it's just that my book says they are built on the II degree of the major mode or on the IV of the minor mode

Your text is correct, there is surely the following reasoning behind it:

If you take the progression indicated by Frank

Bb Re Sol

Bb Re Fa Sol# (DE)

Then V

Re Fa La

Bb Re Sol is IV36 of D minor

omitting from this chord (Bb Re Fa Sol#) the F which is the fifth, precisely Bb Re Sol# ... you will realize that only one note was raised, specifically the Sol (IV degree) which becomes Sol# and thus a #IV.

Obviously you use it on the supertonic (in D minor - specifically Bb) but not on the sixth degree in functional terms

Doing the same exercise for the French [sixth] .... you will have another result, guess what?

Gerardo wrote:

Your text is correct, there is certainly the following reasoning behind it:

If you take the sequence indicated by Frank

bs b re sol

s b re fa sol# (DE)

Then V

la re fa la

Bb re sol is IV36 of d minor
omitting from this chord (bb re fa sol#) the fa which is the fifth, indeed bb re sol# ... you will realize that only one note was raised, specifically the sol (IV degree) which becomes sol# and thus a #IV.

Obviously you use it on the supertonic (in d minor - specifically bb) but not on the sixth degree in functional terms

Doing the same exercise for the French [sixth] .... you will have another result, guess what?

bs b re mi sol# ?

Fox wrote:

sib re mi sol# ?

Putting the notes in thirds order... mi sol# sib re ... you will have some answers

I have some doubts regarding the "functional" reading of augmented sixth chords. They were used long before they were thought of as secondary dominants with a lowered 5th and various nuances. Proof of this, if proof is possible, is that they are named precisely by virtue of a characteristic interval born from divergent chromatic movements and not from their presumed dominant derivation, which in my opinion does not exist. In short, in an augmented sixth, I see more of a second inversion IV degree than a secondary dominant.

Another case is the lowering of the fifth in the bass of a primary dominant, as used at the end of the nineteenth century.

Opinions and subtleties, perhaps useless ones.