Augmented 6ths

[Bob]

Grr!.... I've misplaced my #$%$ theory books. 

I need information about augmented 6th chords.

Can anyone help refresh my mind?

I remember...

There are Italian, French, and German augmented 6th chords.


What is the function?  Pre-dominant?  What type of chords do they come from, and move to?

What's the voice leading for the individual chord tones?

How did these chords come to be?  The historical evolution side.

What poing of music history were these used?   What styles? 


To answer my own questions a little....   and do you find this all correct?....

It +6   is   #4, b6, 1
Fr +6  is    #4, b6, 1, 2     It's the symmetical one
Gr +6 is    #4, b6, 1, #2   It's the one that can be respelled with #2 as b3 to create a dominant 7th and move to a different key right?

I suppose the #4 and b6 are resolving to the dominant and the 1 is moving down to the leading tone on the dom 7. 

There called augemented 6ths because that's the interval from the b6 to the #4.  I don't why I spelled them like that up there then.  The only position for them is in b6 #4, right?     Not much room for inversion because then it's not a +6 interval, right?

I forget if there's anything with doubling certain notes or taking care for certain situations that would produce parallel's...

These chords made me wonder if you could take any group of notes and call it a chord, as long as there's some justification for how the notes move.

[BoliverAllmon]

looks right to me. +6 chords lead to dominant chords. Remember any dom 7th chord can be spelled enharmonically into a Ger +6 and send you into an entirely new key.

for example.

GBDF is V in the key of C. take the seventh and respell it and you get E#GBD which is Ger +6 in the key of B.

Leading tone 7ths can also be respelled into a +6.

BDFAb is the borrowed vii fully dim. seventh in the key of C. lower any one note and you have a Dom. seventh which can be respelled into a Ger +6. for example

BDFAb lower the B to Bb which is the dom in the key of Eb or  respell the Ab into a G# and you now have G#BbDF taking you to the key of F maj.

BDFAb lower the D to Db and you the dom. 7th DbFAbCb (B respelled)which is dom. in the key of Gb or  respell the seventh and you get BDbFAb which is German in the key of C.

BDFAb lower the F to E (to make the spelling easier) and you get EG#BD which is the dom. 7th in A maj. or respell the seventh and you have CxEG#B which is Germ +6 in the key of A flat. (there is no key of G#)

so the original chord BDFAb can take you into the key of
C maj or min.
E flat maj or min.
G flat maj or min.
A maj or min.
A flat maj or min.
F maj.

pretty cool huh?

[Tash]

oh wow let's just freak me out some more! boliver can you come do my uni theory for me please?!!

[BoliverAllmon]

oh wow let's just freak me out some more! boliver can you come do my uni theory for me please?!!

HMMM.... it will cost you. HEHEHEHE

[Tash]

well unless i get this piano teaching job i won't be able to afford it! maybe i should go try opening a text book. i'm sure we'll be learning about augmented 6ths somewhere along the line- just when i thought i new about everything someting bizarrely new pops up!

[BoliverAllmon]

well unless i get this piano teaching job i won't be able to afford it! maybe i should go try opening a text book. i'm sure we'll be learning about augmented 6ths somewhere along the line- just when i thought i new about everything someting bizarrely new pops up!

+6's aren't too bad. Late 19th century techniques are alot harder to descipher.



boliver

[pianomann1984]

Try analysing Scriabin!  fun fun...got a seminar on the evolution of Scriabin's late style to do in May!      mind you it shouldn't be too bad...there's only one chord I need to know - everything else is based on that!!!

[BoliverAllmon]

Try analysing Scriabin!  fun fun...got a seminar on the evolution of Scriabin's late style to do in May!      mind you it shouldn't be too bad...there's only one chord I need to know - everything else is based on that!!!

his music is laced with deceptive cadences and extremely weak cadences in general. (i.e. V-I6/4)