Chord Progressions

Now we get into the part of theory that I think will probably be useful to most of you. We're going to talk about chord progressions. A chord progression is just a series of chords but there's a surprisingly large amount to say about them. Going back to the triads we looked at when we began our discussion of chords, we'll start by only looking at these chords:

In C major:

I Major triad (C major) Tonic
ii Minor triad (D minor) Supertonic
iii Minor triad (E minor) Mediant
IV Major triad (F major) Subdominant
V Major triad (G major) Dominant
vi Minor triad (A minor) Submediant
vii Diminished triad (B diminished) Leading tone/chord

We classify these chords in three ways depending on the function they serve within a chord progression:

Tonic function: I, iii, vi

Subdominant function: ii, IV, vi

Dominant function: iii, V, vii^o

So what does this mean?

Chord progressions work by linking different chords together. While there are no hard rules for writing music consider these guidelines:

Tonic chords can move to any other type of chord.

Predominant chords move to dominant chords or other predominant chords. Often IV will move to I.

Dominant chords move to tonic chords.

When we start examining chord progressions, we'll classify chords based on their function but also based on the importance of their presence. Some chords are more important than others sort of in the way that some sentences in an essay are less important than others. The meaning of an essay may be conveyed more directly in fewer words but having more sentences may serve to soften and smoothen the writing. The same is true in chord progressions. We're going to see a lot of chords that don't do much but are there just to make some transitions smoother. The progression would make sense without these "passing chords" but they're helpful and can make the music flow better. Let's start with the 12 bar blues progression:

In E major this would look like:

| E | E | E | E | A | A | E | E | B | A | E | E |

In our language this looks like:

 I - IV - I - V - (IV) - I

Here we're considering the last A as a passing chord and the progression breaks down to an opening phrase (I - IV - I ) and then a dominant chord (V) moving back to the tonic (I).

8 bar blues:

| E | A | E | B |
| E / E7 | C#m / G#m | A / B | E |

Which is:

I - IV - I - V
I - I7 - vii - iii - IV - V - I

Here we can see tonic moving to the subdominant back to the tonic and then to the dominant. As discussed, the dominant returns to the tonic and then we have a more complicated phrase.

The second line has the tonic moving to the tonic as a dominant seventh chord (this is something we'll discuss later called applied dominance) and then a series of predominant chords final moving to the dominant which returns to the tonic.

Let's have a peek at those rearrangements for Come Together we looked at last time.

The chords that The Beatles use are:

1)

Dm
Here come old flat top, He come grooving up slowly,

Dm
He got Joo Joo eyeball, He one holy roller

    A7       
He got  Hair down to his knee; 

G7
Got to be a joker, he just do what he please.

Now let's look at our arrangements:

2)

Dm                     C
Co - ca   co  - la,   he say
E                E7
I know you, you know me
F                                         A
One thing I can tell you is you got to be free

3)

Dm C       G                          
Co    - ca   co  - la,   he say
A                Bbdim
I know you, you know me
Bdim7               A                 F            G        
One thing I can tell you is you got to be free

4)

F                           C
Co - ca   co  - la,   he say
Am                  
I know you, you know me
Bb                       Bbmaj7              C             
One thing I can tell you is you got to be free

Starting with the first progression. We're in D minor so we have:

1) i - V7 - IV7

2) i - bVII - II - II7 - bIII - V

3) i - bVII - IV - V - bviº - viº - V - bIII - IV

The last one is in F major:

4) I - V - iii - IV - IVmaj7 - V

Some of these are a bit beyond our scope for now but notice that all of them start on the tonic, often have motion from a dominant chord to a tonic chord, and often have motion from a predominant chord to a dominant chord.