#2
http://www.outsideshore.com/school/music/almanac/html/Improvisation/Harmonic_Considerations/Chord_Substitutions/Diatonic_Substitutions.htm

google is your friend

In a nutshell it is replacing one chord with another that has similar notes in it and is from the same major scale.

for example, say we want to substitute C Major for something more interesting.
There are a few different scales C major is in: C Major, F Major, G Major...

Lets take the C Major scale.
C, D, E, F, G, A, B

now C Major has C, E, G in it. If we look at our scale, we can see other chords that have similar notes. For example, Amin (A, C, E) or Emin (E, G, B)


basically, it's substituting one chord for another that has common notes in it. You could take any chord and add a heap of extensions on it, really.
Last edited by mdwallin at Jan 4, 2010,
#3
A Diatonic substitution is when you substitute one chord in a Diatonic Key with another chord in the same Diatonic Key.

General goto Diatonic subs are:

1. for the I chord you can use the IIIm or the VIm. In C that's using a Em or an Am as a sub for C.

Reason being is that the Em(IIIm) is the like a rootless Cmaj7(Imaj7) with M3 5 and M7. Another common one would be the Em11 which is used in Jazz and Modal music a lot, it's much like a rootless Cmaj13 with the M3 6 9 5.

The Am is like a rootless C6 chord (I6 was the goto extension for the I chord years before anyone ever started using the maj7 as the goto I chord extension) with the M3 5 and 6. Another common one is the Am9 chord which is like a rootless Cmaj7/13 chord, or a usable Cmaj13 chord.

3. For the IIm chord you can use the IVmaj7 chord, it's like a rootless Dm9 chord. Think of it as a maj7 chord a m3rd above the root of the IIm chord. In C the IIm chord is Dm, so you's use Fmaj7, which is like a rootless Dm9 with m3 5 9. Another common extension would be Fmaj11.

4. For the V7, or G7 in the Key of C, you can use the VIIm7b5 chord. So for G7 use Bm7b5, it's like a rootless G9 with the M3 5 b7 9.

Those are all pretty cut and dry, but the deeper you get into in you find that the IIm can be related to V7 too, and the VIm be related to the IIm. So, now everything can be considered a substitute for everything!!!

Where you draw the line and how you figure the best ones is...break the chords into Tonic and Dominant properties...

The I, IIIm, and VIm are considered Tonic to the Key and the resolution.

The IIm, VI, V, VIm, and VIImb5 are considered Dominant to the Key and provide tension to to the Tonic.

Use that list above you experiment with what chords can be use as Tonic and Dominant substitutions.

Another thing to look at, and this starts crossing the barriers again, use the idea of "use the chords built from the triad of your chord"...IOW, look at your triad, write the notes in the triad on a of paper, do this for all the chords in your Key.

Next write the triads in the key for EACH note in the original triad...like so in C Major:

C - C Em G
Dm - Dm F Am
Em - Em G Bm7b5
F - F Am C
G - G Bmb5 Dm
Am - Am C Em
Bmb5 - Bmb5 Dm7 F

See how I wrote out the chords in the Key that are found on the notes contained in the particular chords triad?

This is where it gets trick though because you can see that there are Tonic chord contained on Dominant triads, and Dominant triads contained in Tonic triads.

Instead of combining them all go back to the Tonic and Dominant chord idea and remove the parts the crossover between them, leaving...

C - C Em (tonic)
Dm - Dm F (dominant)
Em - Em (tonic)
F - F (dominant)
G - G Bmb5 Dm (dominant)
Am - Am C Em (tonic)
Bmb5 - Bmb5 Dm7 F (dominant)

See how some triadic chords are all tonic and some that are all dominant? And then see the other that crossed over and where removed? Those tell you what might be the best Diatonic Substitutions available to you WHILE playing in Key.

Once you get in to Modal playing you realize the all of the chord in the triad, or the mix of the tonic and dominant chords in a triad, become very useful...because of the tonal center of the Mode, or the I chord being the only thing that matters...not the Diatonic Key anymore.
Last edited by MikeDodge at Jan 4, 2010,
#4
I learned it a little different than MikeDodge but in the end I think it amounts to the same thing. It always pays to get lot's of ways of explaining the same thing.

Here's a post I posted a while back that addresses diatonic substitution after briefly discussing an approach to understanding how chord progressions work.

(Sorry it's so long - feel free to skip right to the diatonic chord substitution part if you want) This does require prior understanding of the roman numeral system and how the major scale numbering system work - if you don't understand something feel free to ask.

****************
You may be curious and asking how and why do chords work together? Well a successful chord progression will provide a sense of tension and release. There are three key things that I think contribute to achieving this outcome.
  • Creating a clear sense of the tonic.
  • How each individual note within a chord moves to get to the next chord and
  • The balance of dissonance and consonance within a progression.


Creating a clear sense of tonic is another whole chapter and a clear understanding of the second point will put you on the right path in this respect anyway. Using dissonant chords is a little more advanced and requires a solid understanding of the first two principles. So I will mostly deal with how to understand chord progressions through analysing the movement of notes from chord to chord.

When looking at the movement of individual notes between chords it would be good to begin with identifying the notes of each chord and relating them to each other by the smallest possible movement between the notes of each chord. For example moving from V-I could be described as each note moving down a perfect fifth.

However, a more helpful view of the V-I progression would be to look for the smallest possible movement between notes. Like so E (E B G#) -> A (A C# E)
  • The root note in the V chord becomes the fifth in the I chord. (E -> E)
  • The third in the V chord moves up a half step to become the new root of the I chord. (G# -> A)
  • The fifth of the V chord moves up one whole step to become the third of the I chord. (B -> C#)


Recognising what individual note movements create resolve or tension is key here. This is gained through experience and observation. In example above the A chord's perfect fifth (E) provides stability and reinforces the A root because of the E overtones present in the A. Having that E already present in the preceding chord makes for a nice transition and really reinforces the tonic (A). The G# is called the leading tone in the A scale. When playing through the A scale the G# tends to create a desire in the listener to hear the A next. The G# provides tension that is resolved in the movement to the root.

Different chord progressions will have create different degrees of tension or resolve.

For Example a iii-I progression provides a sense of resolve as the fifth in the iii moves up a semitone to the root note of the I chord. If we look at the other two notes though, we notice there is no movement at all. This provides consistency and stability making the change smoother and consequently the resolve is weaker than the V-I progression we saw earlier which has only one common note between the two chords.

Not all movements create resolve either. This is obvious as a sense of resolution needs a sense of tension in order to exist. So some movements must create tension that is then resolved. Here is a recommended link that explains Basic Harmonic Function

Another thing to know is chord families and the concept of "reharmonization". They are pretty easy to learn and use.

Diatonic Substitution
The diatonic triads can be split up into "chord families". The triads within each family share at least two notes with the parent chord from the same family. There are three chord families the Tonic, SubDominant, and Dominant

If we take our major scale 1 2 3 4 5 6 7 then the chords built on each note would contain the following notes from the scale:
I = 1 3 5; ii = 2 4 6; iii = 3 5 7; IV = 4 6 1; V = 5 7 2; vi = 6 1 3; vii º = 7 2 4

If we start with the Tonic since it is the fundamental home chord. We work through and find the chords that share two notes with the I chord. These are iii and vi.
This gives us the Tonic Family = I, iii, vi (note a movement between vi and iii requires changing two notes so just be aware.)

Of the chords left the IV and ii share two common notes and together make up the Sub Dominant Family.

And the V and vii chords share two common notes and make up the Dominant Family.

These diatonic chord families are used in a process called reharmonization.

Reharmonization is the process of taking an existing chord progression and making it sound different by reharmonizing a chord (or chords) from the progression with another that belongs to the same diatonic chord family. This way we retain the same basic function of the progression but it can sound quite different.

I'm using colour to identify family members and show how although the chords progressions are all different they family patterns are the same.

We could start with a simple I-V progression for example and use a second member of the Tonic family to reharmonize it as follows:
|I / / / | V / / / | --> | I / vi / | V / / /| We can play around with the timing but the principle remains the same.

A I-IV-V-I might become I-ii-V-I or even I-iii-ii-IV-V-vi
(Just be wary of chord inversions. They are great but using the wrong inversion at the wrong place when reharmonizing can make it sound like the parent chord with one wrong note)

After you have played around with this stuff for a while and feel comfortable with it try learning about some other kinds of chord substitution and how to use extended chords to create a balance of dissonance and consonance in your progressions.

Always keep notes of any observations you make when playing with chord progressions. Figure out what works what doesn't work and either way always try to understand why it does or does not work.

Hope this helps some,
Good Luck
*********************
Si
Last edited by 20Tigers at Jan 6, 2010,
#5
This was good stuff. I'd been independently researching and scribing these ideas on my own, and I am glad to see this, because it confirms what Ive been looking at. It's fascinating stuff. I commonly use a vi7 for a I in substitution, and that got me looking into other possibilities.


Im always looking at different ways to view chords and triads, another example, Ive done a lot of study in, is taking two triads and combining them to create other chords, such as one guitarist playing a Dm triad over a C triad, etc.
Last edited by Sean0913 at Jan 4, 2010,
#6
First and foremost, this article is not for the beginning guitarist. For those who are in the early stages of learning how to play the guitar, please refer to some of my earlier articles. This particular article is geared more in the direction of the advanced professional guitarist. It presumes a very strong background in music theory and a few solid years of guitar under the belt.

Substituting guitar chords and guitar scales can add a tremendous amount of interest to any melodic structure or harmonic structure. Guitar solos and chord progressions take on a whole new life when substitution principles are utilized. Substitution principles add tonal interest and surprise for the listening audience.

Take, for example, a simple ii,V,I progression in the key of two sharps. For the sake of interest, let’s extend each chord to it’s diatonic 7th. Hence, ii mi7, V7, IMa7. This translates to an Emi7(ii mi7)-A7 (V7)-DMa7(IMa7) progression in the key of two sharps. By the way, and as a reminder, a ii, V, I progression is a very strong chord progression for ear training. The ii chord (minor) is an excellent departure away from the tonal center (major), whereas the V chord (dominant in function) is the strongest chord leading back to the established tonal center (major). The ii, V, I progression is very clinical in application. However, it’s a great chord progression to practice and experiment with.
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#7
this discussion is about chord substitution,, right ??
my guitar teacher taught me that if i want to substitute chord i should know the arpeggio`s structure.. like if F major = F-A-C,, then we can substitute it with D minor7 which has almost the same arpeggio structure (D min7 = D-F-A-C)..
#9
Quote by Sean0913
Maybe I missed the "article".. I didn't see anything with a ii V I that showed the idea of a chord substitution, relevant to this discussion.
I think its an adbot - but I'm not sure. They are getting too clever - posting vaguely relevant stuff and putting dodgy links in the post or sig