Jump to content
HAPPY NEW YEAR, TO ALL OUR HARMONY CENTRAL FORUMITES AND GUESTS!! ×

What do you know about augmented sixth chords


IBBIAZ

Recommended Posts

  • Members
Posted

In my constant search for more knowlege, I've come across a new concept that I can't seem to grasp, and that is the augmented sixth chord (Italian sixth, French sixth, German sixth). Basically, all I know about them is that they're predominants. I had a friend try to explain them to me, but I have a feeling that he has no idea what he's talking about.

 

I thought he was right, at first, and tried coming up with a chord progression based on what he told me, but realized that it doesn't resolve to a dominant of the scale - Here's my attempt:

 

progressionre3.jpg

 

 

I honestly have no idea why I resolved it like that, other than the fact that it sounded good, but I don't think I resolved to a dominant in the scale. What exactly did I do here?

 

So basically, I'm asking how do you build the different augmented sixth chords and on what note you build them, and in my attempt, can you see what I ended up doing?

 

Really, I've looked all over, but I either can't understand what the websites are saying or they wsay different things than the other sites. Can someone clue me in please? I'm getting a huge headache from this. :(

  • Members
Posted

ANOTHER augmented sixth chord thread!

 

Yeah, I stumbled over that stuff in theory classes. Can't remember a thing about what makes them Italian, German, French, Texan. I wish they (my music theory teachers) would have linked them to a Willie Nelson or Led Zeppelin tune--then I'd remember what the heck they did.

 

Hope someone in here gets you a good answer.

Posted

Well, your first problem is that the chord in measure three isn't any kind of Augmented 6th chord. So let's back up a moment.

 

 

Yes, augmented 6th chords are predominant chords. As the name implies, they are placed right before the V7 chord in a minor key. Augmented sixth chords began during the classical era of classical music (roughly between 1730 and 1820). The classical era came right before the Romantic era (mostly the 1800's), which featured a lot of chromaticism and new chord types (9th chords, 13th chords, quartal harmony, etc). These augmented sixth chords were a precursor of that era, as they started to push the limits of keys.

 

Originally, these chords were only used in minor keys, but they found their way into major keys as well. However, a vast majority of examples are still found in minor keys.

 

 

The characteristic of augmented 6th chords is the interval of an augmented sixth between the bass note of the chord and another note in the chord, which is often the top voice, but not always. (An augmented 6th is enharmonically a minor 7th). All augmented 6th chords have the b6 scale degree as the bass note. In the key of A minor, that would be the note F.

 

 

If you are familiar with roman numeral analysis, you'll know that '6th' chords are really 1st inversion triads (the third is in the bass). This is where augmented 6th chords get their start. If the b6 note is the root, and that is the 3rd of the chord, then that makes the root the 4th scale degree. Thus, augmented 6th chords are really a variation of iv chords (notice that the iv chord is also a common predominant chord).

 

The simplest of the augmented 6th chords is the Italian augmented 6th chord, which only has 3 different kinds of notes (French and German have 4). If you take a iv chord in a minor key, put it in first inversion, you have a iv6 chord. The root is now a 6th above the bass note (the 3rd of the chord). Take that root and augment it (raise it one half step) to a #4 scale degree, and you have an Italian +6 chord (Notated as It+6 in roman numeral analysis).

 

In the key of A minor, that would be the notes F, A, D#, with the F in the bass. The A and D# can be in any order above that, though the D# is commonly put on top. The reason for that is because when resolving to the V7 chord in the key, the bassnote, F, resolves down on half step to an E, while the D# resolves up one half step, also to an E. The resolution in opposite directions to the same note (in different octaves) is one of the biggest parts of the sound of an augmented sixth chord. To complete the voicing for 4-part harmony, the tonic is doubled (the A in this case). Doubling the b6 or the #4 would result in parallel octaves, since the b6 must resolve down and the #4 must resolve up. When resolving to the V7 chord, the tonic will resolve down to the 7th scale degree, which is the 3rd of the V7 chord (G# in the key of A minor). If there are two tonics, such as in four part harmony, one will resolve down to the 7th scale degree and one will resolve up to the 2nd scale degree (the notes G# and B, respectively). The two tonics can be, and frequently are, in the same octave.

 

The French augmented sixth chord is exactly the same, except that one color note is added to the chord. In this case, the 2nd scale degree of the key is added. The result in the key of A minor would be the notes F, A, B, and D#, with the F in the bass. Since there are already four notes, no doubling is needed for four part harmony. When resolving to the V7 chord, the new note, the B, stays the same (since B is a part of an E7 chord). A French augmented sixth chord is notated as Fr+6 in roman numeral analysis.

 

The German augmented sixth chord follows the same trend, except that the 3rd scale degree of the key is added instead of the 2nd. The result in A minor would be F, A, C, D#, with the F in the bass. Enharmonically this is an F7 chord (a bVI7 chord), though it is always spelled with a D# instead of an Eb to reflect the agumented 6th interval. Again, this chord already satisfies four part harmony. When resolving to the V7 chord, the new note, C, must resolve up to the 7th of the V chord, D. If it resolves the other direction, down to the B, parallel 5ths result between the F and C moving to E and B. A German augmented sixth chord is notated as Gr+6 in roman numeral analysis.

 

 

 

Here is a much easier way to construct these augmented 6th chords, using the scale degrees of the minor key:

 

First, for all augmented sixth chords, put a b6 scale degree in the bass, and a #4 scale degree above it.

 

 

For It+6, above the bassnote, add the tonic, twice if using four part harmony.

 

For Fr+6, above the bassnote, add the tonic and 2nd scale degree.

 

For Gr+6, above the bassnote, add the tonic and b3 scale degree.

 

 

 

Example:

 

In the key of C minor, the starting notes are Ab and F# (b6 and #4). By adding the appropriate notes:

 

It+6: Ab C © F#

Fr+6: Ab C D F#

Gr+6: Ab C Eb F#

  • Members
Posted

Hey there,

 

that chord you labled as French 6 isn't really a Fr 6th in A minor... Matter of fact it is a I7-42 (basically third inversion of a A dominant chord)

 

The most basic Augmented 6th would be the Italian which in A minor would be D#, F, A. Given that it is 6th chord the F would be the bass note.

French 6th would be F, A, B, D#, and German 6th would be F, A, C, D#. There are more variations but they generally all come from these three chords.

 

The most basic way to figure out a Augumented chord for any key is to remember that the most basic form of it is a iv chord wth the root raised a half step.

 

Say you are in C minor. The iv chord will Fm. You raise the F to F# then you get a root position Italian chord. Given that it is 6th chord, Ab is going to be on the bottom and you have yourself an Italian 6th.

 

Another way to think of it is that this is a subdominant chord and what makes it really subdominant is the raised root because it acts as a leading tone. For example, in A minor the D# is going E, the root of the V chord.

 

Anywho as for the chord progression... I think what you are going for is Aminor-F major- A dom- Ab maj.

G#=Ab, C is C, and D#=Eb. Ab-C-Eb is a Ab major triad. Approaching a tonic from half step above the root is very common, and is basically a tritone sub. So cool progression, but nothing to do with Aug 6th chords unfortunately...

 

If you want a really nice website that explains it in the most simple terms check out this one, http://www.teoria.com/reference/chords/17.htm

  • Members
Posted

I just noticed that popard posted while I was typing. His is really nice and more informative than mine I think but i hope mine helps too.

  • Members
Posted

I was told to NEVER open the spam email with the title: "With Medical advancements, you can now augment your 6th chords" ;)

 

 

Great read Pop and Chris. I'm going to check this out this weekend, along with that utexas site which had notation and audio of these in practice.

 

I've read a bit about this, but...

 

Some of this almost sounds like the simple movement during the last measure (with a pickup) of a blues progression where you move into the last V7 chord by approaching in from a half-step above...on a basic level anyways. ANd, regardless if it's a Major or Minor blues.

  • Members
Posted

Originally posted by gennation

I was told to NEVER open the spam email with the title: "With Medical advancements, you can now augment your 6th chords"
;)

 

Are you saying you're never tempted to try to augment your 6th chords? I mean sure, most of it's junk, but we all get curious sometimes...

  • Members
Posted

Originally posted by bardsley



Are you saying you're never tempted to try to augment your 6th chords? I mean sure, most of it's junk, but we all get curious sometimes...

 

Hey, if god gave me a 6th chord...then I'll just have to live with it ;)

 

Sure I could walk around showing off my augmented 6th chord...but, I'll just have to live with the regular 6th chord I recieved. I'm good with that :)

  • Members
Posted

 

Originally posted by gennation

Some of this almost sounds like the simple movement during the last measure (with a pickup) of a blues progression where you move into the last V7 chord by approaching in from a half-step above...on a basic level anyways. ANd, regardless if it's a Major or Minor blues.

 

 

You see--that's what I need. While I frequently listen to Classical and Baroque music, I frequently play blues (-influenced) music. So ... what T-Bone Walker tune does the aug6th chord occur? It's gotta be the French kind, since T-Bone's so refined!

Posted

 

Originally posted by Stackabones



You see--that's what I need. While I frequently listen to Classical and Baroque music, I frequently play blues (-influenced) music. So ... what T-Bone Walker tune does the aug6th chord occur? It's gotta be the French kind, since T-Bone's so refined!

 

 

 

What blues players like T-Bone use aren't augmented sixth chords, but they just happen to sound a lot like them. They're simply preceeding the V chord by playing it up one fret. I'm 99% sure they have never heard of augmented sixth chords, let alone have any idea how to use them.

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...