Classical augmented sixth chords
 

Italian 6th chord
a.) in first inversion
b.) flat 6 - 1 - #4
c.) double the tonic
d.) resolves to a 1 6/4 chord

German 6th chord
a.) flat 6 - 1 - 3 - #4
b.) resolve to a 1 6/4 or a V chord


French 6th chord
a.) flat 6 - 1 - 2 - #4


What are special about these chords ?

Why does classical composers use these chords?

How are there chords used ?

the chord is an Italian sixth; when an augmented fourth is added above the bass, the chord is a French sixth; while adding a perfect fifth above the bass of an Italian sixth makes it a German sixth (the etymology of all these names is unclear). All usually have the flattened sub-mediant (sixth degree of the scale, A flat in C major, for example) as the bass note -in this case, they tend to resolve to the dominant.

Augmented 6th Chords:

• The name "augmented 6th chord" refers to the interval of an augmented 6th between scale degrees b6 and #4.
• The augmented 6th chords are a type of chromatically altered chords like the secondary dominant, secondary diminished 7th, and the Neapolitan 6th chords. Augmented 6th chords arise as a result of voice leading; there are no real roots. The b6 scale degree in major (or scale degree 6 in minor) occurs most often in the bass. All the chromatically altered notes should resolve in the direction of their alteration; b6 resolves down to 5 in the bass and #4 up to 5 in an upper part.
• The augmented 6th chords often occur near cadences. They usually resolve to the tonic six-four and then to the dominant, especially the German augmented 6th chord, to avoid parallel 5ths.
• The four types of augmented sixth chords are summarized as follows:

It deserves note the English sixth which is equivelant to the german sixth resolving directly to the tonic (the distinction).

It also deserves note that the aug six chords form enharmonic equivelants to tritoned alt-7ths in jazz form (D7-Dbalt-C, where the Dbalt is enharmonic with some form of aug6).

Not meaning to hijack or anything, but since you're on a roll I thought I'd throw that in.

Helpful links:
http://www.ibreathemusic.com/forums/...7064#post57064
http://music100.music.indiana.edu/so...11/chords.html

Key of Am:

Italian +6: (bottom to top) F A D# F

French +6: F A B D#

German +6: F A C D#


The bass in those examples must be an F, but the top three voices don't have a specific order as long all of the notes are present.

Where the chord exists:

Aug6th - V7 - i

(right before the V7 chord)

I don't understand its "flat" 6th not "Sharp 6th" or are these different chords
because its Minor?

because you wrote +6 and i wrote b6 in my harmony book

The chords are named for the #6 or augmented sixth interval found between the b6 scale degree and the #4 scale degree.

In Am, any +6 chord will have the notes F and D# (b6 and #4), which form an interval of an augmented sixth.

Thanks for the information

The chords are named for the #6 or augmented sixth interval found between the b6 scale degree and the #4 scale degree.

Are you saying on the "flatted 6th scale degree" the interval is a #6 and #4?

How can a #4 scale degree have a augmented sixth interval?
How can a b6 scale degree have a augmented sixth interval?
how can a #6 scale degree have a augmented sixth interval?

In Am, any +6 chord will have the notes F and D# (b6 and #4), which form an interval of an augmented sixth.

Are you saying a (b6 and #4) = #6

The interval between b6 and #4 is an augmented 6th.

Just like in a major key, the interval between 1 and 3 is a major 3rd or the interval between 1 and 5 is a perfect fifth. In an augmented sixth chord, the interval between b6 and #4 is an augemented 6th.

Thanks for making it clear

The French 6th chord has a Augmented 6th interval and a suspension because of the 1st and 2nd intervals

French 6th chord
a.) flat 6 - 1 - 2 - #4

here is the formula to make the french 6th chord it has a suspension the 2nd
plus the augmented 6th interval