CHORD SUBSTITUTIONS Any chord can be substituted for another which has the same tonic, dominant or traveling function. A substitute chord, or series of substitute chords, can provide alternate harmonic paths while maintaining its original function. function. (Two different V7 chords can provide the same dominant dominant function wit h different harmonic conclusions, for example.) Or, the substitution can imply two functions simultaneously. (As will be seen below, with the help of an altered pitch, a chord can be heard as having both a traveling and dominant function.) Three types of substitutions which occur frequently are the tritone substitutions , the omitted/added root substitutions , and circle progression additions .
The Tritone The tritone substitution is a dominant 7th chord whose root is a tritone (3 whole steps) away from the original dominant 7th chord. The chords are interchangeable because the tritone interval pitches are identical in each. Chord substitution often results from an attempt to provide smooth voice leading. Using the tritone substitution, the roots of the ii-V-I progression move down by half-steps, instead of ascending 4ths. For example, in the key of C the progression becomes Dm7, Db7, CM rather than Dm7, D m7, G7, CM.
OMITTED/ADDED ROOTS The omitted/added root substitution exchanges the root of the given chord for a root a third or fifth higher (occasionally lower.) The substituted chord still r etains several pitches of the original, implying the same har mony, but but can also a lso point toward different directions--both directions--both in key and function. Example B depicts a G7 chord with various omitted-root substitutions. The B dim. 7 chord, with 3 pitches in common with the original, retains the dominant quality, as it contains two tritone intervals. At first glance it seems to share an identical function with a G7 (b9) chord, yet, because G is omitted as the root, the diminished 7th chord offers additional possibilities of resolution. In short, unlike G7 (b9), B dim 7 is as likely to resolve to A Major or Eb Major as C Major. The G7 and Bb7 chords have two pitches in common and, along with their dominant 7th constructions, constructions, generate enough similarity to share a dominant function but also enough diversity to provide pathways in different directions. (The obvious resolution of Bb7 is in the key of Eb and the G7 is the dominant of C.) Because of common pitches and the presence of a tritone, D-7 (b5) can also be a dominant substitute for G7. At the same ti me, however, its root, a fifth higher, higher, also has a traveling function. As the ii chord in the key of C, the D-7 (with its altered 5th) allows the progression to extend itself before progressing toward a dominant and eventual tonic.
CIRCLE PROGRESSIONS PROGRESSIONS
Circle progressions, as well as being fundamental to the structure of many traditional jazz compositions, are often inserted as turnarounds (discussed above) or used as a series of substitute chords in specific parts of a composition. Example C, below, shows both a basic 12-bar blues progression (in black letters) and s everal circle progression substitutions (in red letters), which are used to amplify the structure. Not only do the added substitutions provide tension by their harmonic direction, but also by the quicker harmonic rhythm. You can note the effect of this by pushing the "play" button to see how the progression occurs in real time. Can you decide how the specific substitutions might be chosen? I wrote a blues called, "Wildwoman Blues" for my students some years back which was used as a sight-singing exercise. It seems appropriate to bring it back for your analysis (be able to discuss in class) and, oh yes! as a sight singing exercise (to be sung in class). Many different dominant 7th chords here--some have tonic function, others dominant function. There are example of tritone substitutions, and many instances of circle progressions. Find out what you can. You can hear a synth version in the example below by pushing the "play" button. The singing exercise should be in three stages: first sing the roots of the chords as they occur in the form, then sing the melody. Finally, improvise over the progression (use only chord tones!) while someone else sings the bass line!
A Chord Substitution Primer By Darrin Koltow from the ebook Guitar Chords: a Beginner's Guide "What's wrong with a song's original chords? Why go through all the fuss to tamper with something that already works?" Yes, what is the point of chord substitution? Chord substitution is a bit like spring cleaning for music. You get tired of looking at the same old junk that's been lying around the house for the past year or so. You're not sure what it will feel like to have a clean house, but you know the cleaning has to be done. With chord substitution, the "junk" you're getting rid of is the boredom you feel in playing the same song the same way over and over. Replacing some chords with other chords adds new life to a tune. Let's look at some ways we can substitute chords in a simple but useful tune. The tune we're using to make changes is the same one in the article How Chord Progressions Work . I call it the Sam Cooke song. Substitution One: "Musician's Math"
Here are the chord changes to the Sam Cooke song, together with the chord substitutions. These new changes will give us a fresh perspective on this golden oldie. They'll also help us understand some principles, or guidelines , really, for chord substitution. Here's the original progression: ||: C
Am F
G7
F
C
F
Am G7 C
G7
C
G7
C
D7
D7
F
G7 D.C. al fine
C
:||
And here are the new chords. ||: Em Em
Am Dm
G7 :||
F
F
Em
Em G7 C
Dm Am C
Dm Am C
F
Dm
F
G7 D.C. al fine
A quick note on notation: The "Fine," referred to in the "D.C. al Fine" is the fifth bar in each of the chord progressions illustrated in this article. So for the first progression shown, end on the C major chord. Here are some guidelines used in creating the new chord progression: y y y
One equals three equals six Two equals four and Five equals seven
Welcome to Musician's Math. L et's explain these. Look at the following figure, which shows the chords in C Major. "One equals three equals six" means the C major chord (the One), the E minor chord (the Three), and the A minor chord (the Six) sound enough like each other to replace each other. They do sound different from one another, but compared to the other chords, they sound similar enough to serve as substitutes for one another. Letter
C
Roman numerals I
Dm Em
F
G7
Am Bhalf-dim*
ii
IV
V7
vi
iii
vii*
Plain old English One Two Three four Five Six Seven *The b* means "b half-diminished," which is kind of like a minor chord, but really closer to a G7 in its overall sound.
That means when I see a C major chord on a song chart, I can try out an A minor or an E minor instead. The sound I get might or might not be an improvement. If it isn't, it probably won't sound bad. "Two equals four" means I can substitute D minor for F major. "Five equals seven" means I can substitute G7 for b* and vice versa. Substitution Two: All Minor Chords
First, here again are the original changes: ||: C
Am F
G7
F
C
F
Am G7 C
G7
C
G7
C
D7
D7
F
G7 D.C. al fine
C
:||
And here is the progression using just minor chords. ||: Em
Am
Dm
B half dim :||
Em
Am
Em
Am
Dm Em Am
Em
Am
Em
Am
Dm Am
Dm Am
Dm
Bhalf dim D.C. al fine
There's a chord in there you might not be sure how to play. It's a B half diminished.
How it works I applied the "One equals three equals s ix," "Two equals four," "Five equals seven" talked about a little while ago to make these changes. For the first bar, I asked what I could swap out C major with, and came up with E minor. I could have chosen A minor, but E minor sounded better to me. Substitution Three: V to I
This next "change on the changes" is call ed Five to One. Play these changes, then read How it Works to learn what gives this progression its distinctive sound. Here again are the original changes: ||: C C
Am F
G7
F
C
F
G7
C
Am G7 C
:||
G7
C
D7
D7
F
G7 D.C. al fine
And here are the V7-I changes. ||: C E7
Am C7 F
D7 G7 :||
F E7
C C7
F E7
Am G7 C
Dm G7
C A7
Dm G7 C A7
D7
D7
F Dm
D.C. al fine
C C7
G7
How it works The idea is to pretend certain chords are One chords, which is like starting a new key. When we do that, we can precede the One with its dominant 7 chord, (called its "Five" chord). A Five to One movement always sounds good. We've just touched on the basics of chord substitution, which is a huge subject. This is another way of saying there are infinite ways of ma king a great tune sound even greater, and giving a crummy tune a chance to mend its ways. Taking the time to learn more about chord substitution will pay off in greater enjoyment and interest in your playing.
STRONG and FRAGILE PROGRESSIONS (all given in C -major): Simple progressions can be categorized as either being strong or fragile. A strong progression is one that clearly points to one note as the key, or tonic, note. They can be used anywhere, and are great especially for chorus melodies, which usually rely on the strong indication of a key. Strong Progressions (To see these progressions in fretboard/musical staff notation, click here.)
1. 2. 3. 4. 5.
C Dm G C C Dm7 G C C Fmaj7 G7 C C Am Dm G C C Em Am Dm G7 C
A f ragile progression is one in which a specific chord is not clearly indicated as being the only possible tonic chord. Such a progression, on its own, could point toward two or
more chords as being possible tonics, and usually require a strong progression after it to make the clear determination. Fragile progressions can be used anywhere, but work very well in verse melodies. Keep in mind that most multi-chord progressions are a mixture of strong and fragile elements. (To see these progressions in fretboard/musical staff notation, click here.) Fragile
1. 2. 3. 4.
Dm7 Em7 Am G F G Am Em G Am Em Dm F Am C Gm7 Am7 BbMaj7
PROGRESSIONS THAT END ON A DIFFERENT CHORD (DECEPTIVE CADENCE): Deceptive Cadences (To see these progressions in fretboard/musical staff notation, click here.)
1. C F Am G F 2. C Dm G Am 3. C Am Em G Ab
PROGRESSIONS THAT USE DIMINISHED CHORDS: (What's a diminished chord?) Diminished Chords (To see these progressions in fretboard/musical staff notation, click here.)
1. C F Fdim7 C 2. C Dm Bdim C 3. C C#dim Dm G C
PROGRESSIONS THAT USE INVERTED CHORDS: (What's an inverted chord?) Inverted Chords
1. 2. 3. 4.
C C/E F G C C G/B F/A G C C G/B Am F G G/B C C G E/G# Am G/B C
PROGRESSIONS THAT USE SECONDARY DOMINANT CHORDS: (What's a secondary dominant chord?) Secondary Dominant Chords
1. 2. 3. 4.
C A Dm G C C E A Dm G C CFDGC CDGC
PROGRESSIONS THAT USE MODAL MIXTURES: (What's a modal mixture chord?) Modal Mixture Chords
1. 2. 3. 4.
C F Fm C C C/E Fm G C C Eb F G C C F Ddim G C
