phb - Posted - 01/15/2021:  03:07:37

Asked from the perspective of a bluegrass 5-string picker:

I know basic chord theory. I know that a dominant 7 chord can be interpreted as a diminished chord plus the root note of the dominant chord which leads to some interesting use cases for diminished chords and their related inversions. E.g. with a little thought I can find a diminished chord close to any major chord that resolves to that major chord such as 6-6-7 (1st to 3rd strings in open G tuning) resolves nicely to the C chord at 5-5-5 and 9-9-10 resolves nicely to the C chord at 10-8-9 even though neither chords are obvious (partial) G7 chord formations. I can find them by moving a partial G7 chord (F-formation) up and down the neck in multiples of 3 frets. This seems like a useful tool.

I know how an augmented chord is constructed. But what can I use it for? It also sounds like it wants to resolve (but less strongly than the dim and G7 due to the lacking tritone) so that one can use a G+ instead of a G7 such as 1-0-0 to 2-1-0, 5-4-4 to 5-5-5 and 9-8-8 to 10-8-9, right? So this is just an additional colour in the sound palette that can be used where 7-chords are used? Am I overlooking anything important here?

janolov - Posted - 01/15/2021:  04:03:28

If we are talking about Bluegrass and Old-Time banjo music I think augmented chords are very rare. In other genres (I think of Rag-time and jazz) augmented chords are used as "passing chords" in chord runs. So often it is not the chord in itself that is important, but more the effect together with the chords before and after.

Greg Denton - Posted - 01/15/2021:  04:09:33

It's great for transitions. Try playing C - C+ - Am for instance.
C = C, E, G
C+ = C, E, G#
Am = C, E, A
So, an augmented chord makes a nice step between any major chord and it's relative minor.

Try G - G+ - Em
Try D - D+ - Bm
etc.

Tractor1 - Posted - 01/15/2021:  04:54:10

pretty much what Greg said.

mmuussiiccaall - Posted - 01/15/2021:  06:03:27

Everyone in the band has to be informed when an augmented triad is coming so they can adjust because in bluegrass especially they are playing a lot of "root fifth" accompaniment. Even playing just by ear it would be an obvious "bad sound" otherwise.

Tractor1 - Posted - 01/15/2021:  06:22:55

the hippie grass song "with care from someone" used it about the same as Greg mentioned , resolving to the relative minor with out accidentals in the scale is a full 2 semitones, and does not resolve as good as a half step imo -I ask no one to agree or adopt this thought though

Alex Z - Posted - 01/15/2021:  06:25:46

A few observations:

  -- An augmented triad forms an augmented chord for each of the three notes in the triad.  For example, C aug has the same notes as E aug and G# aug.  Consequently, in music more complex than bluegrass, there can be a choice of resolutions, useful in modulating from one key to another.

 -- A more natural sounding resolution of C aug is to the major a fourth above (or a fifth below) -- F major chord.   The G# note resolves to A, the E resolves to F, and all is right with the world.    So as Mr. phb mentions, an augmented chord can function the same way as a dominant 5th, although to my ear the sound is quite different from a dominant 7th chord and I wouldn't think of substituting one for the other.

 -- Other than in formal analysis of classical music, augmented chords are often "spelled" for convenience, rather than for function.  For example, that C aug chord (C-E-G#) might be "spelled" as and called an Ab augmented chord (Ab-C-E) in sheet music.  In short, if you're working from sheet music or improvisation, how the chord sounds and functions are the most important things.

Hope this helps.

beegee - Posted - 01/15/2021:  06:43:01

I have a guitar-playing friend who calls them "argumentative chords"

ocarina-man - Posted - 01/15/2021:  07:49:16

Try playing California Here I Come or Running Wild without them.

Richard Hauser - Posted - 01/15/2021:  08:31:22

I have been using them for the decades I have played. I was not aware of that until I studied Bill Knopf's Banjo Workshop 2. Knowledgeable use of chords makes chord transitioning better sounding and can make the melody more distinguishable. Generally speaking, there does not seem to be much interest in that subject in BHO.

Fathand - Posted - 01/15/2021:  18:44:52

Sometimes they work where you might use a 7th chord.

Richard Hauser - Posted - 01/17/2021:  07:42:27

Dominant 7ths are abused as much as they are used. Especially by guitar players. Using something too often can reduce its effectiveness.

Tractor1 - Posted - 01/17/2021:  08:34:54

It kinda shows in Blue Skies

Tractor1 - Posted - 01/17/2021:  08:38:41

Oh I forgot in Georgia The C aug trades places with the f chord at half measure about 4 times in a row for the fillin. Doing it down the neck in various places for a walk down effect