PG Music Home Forums General Discussion Woodshedding - Learning to Play! What are the most common functions of diminished, augmented, and m7b5 chords ?

Hi all,

Many books will teach you a 'silly' amount of fingerings for all the different chords, but far fewer - maybe none that I have run across, that take a chord quality and explain the function of that chord in a variety of song contexts. Also, these books will build diatonic structures in a 'silly' amount of tonalities, and again - have very few examples regarding function.

Can you guys help me get started understanding the most common functions of the above qualities, maybe reference some good song examples, and some exercises to help me incorporate these songs into compositions and cool substitutes ?

Again - I have a LOT of books - but none do justice, IMHO, to this question. Maybe I just have the wrong books for this aspect of music.

Can you properly harmonize a Major scale in any key on yer guitar?

Example: Play an E Major scale in one octave using the correct chord for each step. M-m-m-M-M-m-dim7-M

If not, then it is not time to be concerned with these chords yet, for they will not make much harmonic sense.

The function of those three chords is to provide the scale-generated harmony for the notes in between the notes of the given scale.

Look up "scale harmonization" for starters.


--Mac

Mac - I've got the part you described, I just can't seem to make the jump to using that stuff in songs and compositions. Maybe I'm more concrete - I'm looking for some more song examples and particular progressions that use them. Thanks again for all your support and help over the years.

Examples of usage in songs, start investigating the chord changes to the great old standards, ballads, jazz standards. Realbook, etc. Tin Pan Alley songs forward.


--Mac

A good understanding of music theory will help you to understand them a bit more.

Also study the kinds of music that use them..... Jazz is a really good place to start.

I write a lot of country and to be honest, there generally isn't a big need in country for those chords.

You can also study this right inside Band in a Box.

Use the MELODIST function.....select Jazz and one of it's subcategories and let it generate a number of "songs". Depending on the style it is using, you will find these chords used right there in BB. Study how it is applied.

The Band in a Box Demo songs are another place to study use of chords in progressions, too.

The Jukebox can load all the songs in one demo folder and play them, you can stop the jukebox when one loads that looks interesting and have a go at it.


--Mac

...and so I begin following all those suggestions. Thanks for the encouragement and reminders.

Love the sound of these diminished chords. they also lay so well on the guitar neck and given that they are symetrical there is lots of cool voicings.

Charlie has a good writeup on these:

http://charlieaustinjazz.blogspot.com/2012/03/diminished-perspectives.html

tutorial videos featuring Tim Cummiskeylooked like they may be useful for this thread




https://www.youtube.com/user/SPGGuitar251/search?query=Tim+Cummiskey

Google II - V - I functions. Lots of info out there. Later, Ray

To try to answer the question, applies to your other post too Joe.

Diminished chords bring tension.

Music is about tension and release.

Release tends to be strong beat major and minor chords.

In between there is space for tension, diminished chords can fit in here, preceding the resolving chord, often preceding by a diminished a half stelp below

The augmented fifth chord, is basically a dom 7th chord with an extra bit of color, a common place for one of these is the last chord of a twelve bar blues. Try a 12 bar with a 7th chord built on the fifth of the key, then an aug 7th, you will hear a bit of extra spice and yearning to get to the root chord on bar 1 of the second chorus.

Basically all these none standard chords bring tension, they heighten the tension.

the minor 7 flat five is a Locrian chord, in C its all white nbotes based on the 7th - B. I think of this as a standard, unchanged modal chord. If you work it out this chord is strongly related to the dominant 7th as it shares three notes with it.

Maybe you need to play and hear these chords in action. Wrap your fingers around this little ditty:

Note stack for the 5th chord Am7b5 is NOT correct, actually there are quite a few discrepancies in that example, such as that A# in the Gm7, etc.

The chord diagrams look to be okay, but the notes given are not to be trusted. Charted by Kent Reed?

The source of this score goes back a long way (~20 yrs?). I suspect it may have originated in some form in a Guitar Player Magazine. I think I added the chord charts back in the day likely based on how I played the piece more then how it is actually notated.

I did some hunting this morning and was able to confirm that I did add the chords based on my playing but did not change the corresponding notation. So in fact there are two versions above, one for the guitar player and one for keyboard (no extra charge).

I just redid it after all these years and notated the way I play it on guitar. I'm always open to corrections?


So now that you have seen it and played it, lets drop in BIAB so you can hear it and understand why jazz cats love these changes.

12 Bar Minor Blues - augmented and diminished chords - BIAB 2014

You're first example shows something that happens when someone makes the error in thinking that since Sharps and Flats share "the same note" that there is no reason to deal with both.

Convention, however, is there because the music notation rules are based on more than 300 years of input and development. When we first encounter notation, it is a rather common thing to think that the conventions used are either superfluous or otherwise not as easy to deal with, I can recall thinking the same sort of thing about certain notation functions at one time.

As with many subjects, the more exposure and experience gathered is important, those conventions and such then start to make much more sense as to the rhyme and reason behind them.

Then we start to realize the wisdom in those rules of notation and such. We figure out why, for example, a Gm7 chord notation will always be done with a Bb and not an A# in it. Or a b5 chord that uses a SHARP in the notation. Sure, it is the same fret on the same string, but when I view a Sharp - I'm automatically thinking "Augmented 4th" which immediately makes me think, "Classical Music" when we are dealing with a Jszz chart, where the thinking should be "Flat 5, man"...


And others will be able to read our charts much faster and easier, because the chart will contain the certain conventions that everyone is accustomed to using.


Just keep dealing with the thing, as you show well that you are here, for that is what we as journeymen musicians should *always* be doing from cradle to grave. I think I've always been able to hear and play things before being able to properly notate same. It had to change the day long ago when I took on the task of Copyist for a bigband, moving from there to the beginnings of trying my hand at my own Arrangements. Other musicians can be very cruel when one darn little thing on the chart ain't right.

Straightahead,


--Mac

On the point of the history of notation Mac, I can see where you are coming from and all the points you raised are true, however my view (only mine) is that the notation system is cumbersome. English is similar because it has grown from a hotch potch of needs and conditions and influences, it has so many anomolies and illogicalities, grammar is needlessly complex.
Same with music notation, it was first developed before Fux in the days of Church Modes as a few scratchings on the sides of manuscripts before the concept of the major scale was properly developed (as we would see this) when some intervals were associated with the devil and when there was no equal temprement instruments - notation was mainly for choirs and plain (type) song.
It was also developed to be facilitated by the scratching of the quill pen - lines squiggles and blotches
As time proceeded notation was hacked and used to suit various instruments and settings - in a hotch potch fashion.
Unfortunately we were still left with needlessly terrifying terms such as "Mixolydian" "Appogiatura", sforzando and many more " (OK I can't spell them).
If basic things were put more simply we would all learn doppio movimento to put it in notation terms.

I have deep sympathy for anyone trying to learn notation, many are put of by its needless obscurities. There is a lot of damage done by the classical route education (IMO)

I am on my soap box....I admit

Zero

The more one actually works with it, and that means sight reading rehearsals as well as home practice, using notation in actual scoring work, etc. - the more one is likely to find out the wisdom involved in how notation is done today. Notation and language are two manmade things that actually do evolve over time, solving problems.

Over the years I've seen several different attempts to create a new music notation system that was supposed to be simplified or somehow "better" and none of them were, all were rather abysmal because they left out some important factors here and there.

Anyway, it is what it is, those who do not have a daily need to use music notation will likely always see that differently.


--Mac

Really great examples and discussion - thanks for sharing, it's really helping me out. I'm following all the suggestions, and Mac - I confess - I can NOT fluently harmonize the scales in any reasonable musical tempo - still working on that : )

Mac has a good point in suggesting to Harmonize a major scale.(I didn't know it was called Harmonizing a scale)

Chord selection can be seen as providing context and direction to a melody.

Context provides a background against which the melody note will be heard. If the melody note is member of a the chord, the chord provides consonant support. If the note is not a member of the chord, the listener knows that the note is "less important", perhaps only a passing dissonance in the grand scheme of things.

Direction refers to how the harmony and melody unfolds over time. For example, stronger chord movements (movement of roots by fifths) may imply a stronger cadence, while a more linear progression (inversions where roots move stepwise) may imply a weaker and more local movement.

One way of measuring the dissonance of a chord is by the harmonic intervals. Using the overtone series as a guide, the strongest interval is the octave/unison, followed by the perfect fifth/fourth, and then the major third/sixth.

The perfect fifth is a very strong interval, second only to the octave/unison. In both the diminished and augmented chords, it is subverted. The diminished chord also has a minor third instead of a major third, but this is secondary to the diminished fifth.

If you think of chords as coming out of scales, the diminished chord comes "naturally" from the diatonic scale, starting on the 7th degree of the major scale.

C major scale = C - D - E - F - G - A - B - C

B dim chord = C - D - E - F - G - A - B - C - D - E - F - G - A - B - C

With no perfect fifth or major third, it's a very weak chord. Since it's built on a stack of minor thirds any the notes of the chord have equal claim to being the tonal root of the chord.

In this context, a dim7 is a stack of four minor thirds. Again, any of the four notes could make equal claim to be the tonal center.


In contrast, the augmented chord doesn't appear "naturally" in diatonic scales. While the diminished chord doesn't imply any harmonic direction (all the notes of the chord could equally be called the root), the augmented chord very much creates an interval which needs to be resolved.

Hopefully this information will help explain why you might choose to use these chords:

1. You might choose to use a diminished chord in a place where you need to provide consonant harmonic support to passing tone, but don't want to draw attention to it.

A typical example of usage here might be where you've got some horns on a part, and the melody has a passing note, such as C - D - E. The overall harmony in the example is C major, but (for the sake of discussion), let's say you want to put a consonant chord under the passing D note.

In theory, you could choose to harmonize the D note with something like a G7 chord:

C -> G7 -> C

But a G7 is harmonically strong, and would draw a lot of attention to that point. You could choose another diatonic option (chord drawn from the scale) such as:

C -> Dm -> C

...but even that might be too strong. On the other hand, if you chose a really weak chord (such as a diminished chord):

C -> Ddim -> C

Voila! You have harmonic support (so the horns have motion) without drawing too much attention to that particular note.


2. You might have a linear bass line over a held chord. For example, the progression:

Am -> Am/G# -> Am/G -> F#dim -> Fmaj7

can be seen as:

Am -> Am/G# -> Am/G -> Am/F# -> Am/F

The diminished chord arises over a held chord (Am) over a moving bass line.


3. In a jazz context, a diminished chord can be seen as dominant 7th chord without a root. For example, G7 = G+B+D+F. Bdim = B+D+F.

So G7 = Bdim/G


4. Unlike a diminished chord, the augmented chord calls a lot of attention to itself. It's typically used to add a chromatic movement to a progression, with the progression resolving by continuing the motion up another half-step. For example:

C = C+E+G -> Caug = C+E+G# -> Am = C+E+A

Here, using the Caug provides consonant support for the G - G# - A melodic movement.

Often, the chromatic movement may appear in the melody, but it may appear in the root of the chord instead. In the example above, it's just a chromatic embellishment to a simple C -> Am progression: interesting to hear, but just a passing motion in the grand scheme of things.