Music Theory - Diatonic Chord Progressions
This lesson is intended to give a basic understanding of harmonic function related to a major key.
Contents
Harmonic Functions
At the most basic level of abstraction, each diatonic chord has one of three functions: tonic, pre-dominant, or dominant. The function of tonic chords is to establish tonality or resolve tension. Thus it is often the first and/or last chord in a song. Dominant functions to create tension that can be relieved by tonic chords. Pre-dominant chords serves to lead into dominant chords. Here is a table with all the diatonic chords and their function:
| Chord in C Major | Harmonic Context | Name | Parallel of | Harmonic Function |
|---|---|---|---|---|
| C | I | Tonic | Tonic | |
| Dm | ii | Supertonic | IV | Pre-Dominant |
| Em | iii | Mediant | V | Tonic/Dominant |
| F | IV | Subdominant | Pre-Dominant | |
| G | V | Dominant | Dominant | |
| Am | vi | Submediant | I | Pre-Dominant/Tonic |
| Bdim | vii° | Leading | Dominant |
This gives us our first and most basic chord progression: I - IV - V - I:
fig 1 C F/C G/B C I IV V I e--0-----1------3-----0---- b--1-----1------0-----1---- g--0-----2------0-----0---- d--2-----3------0-----2---- a--3-----3------2-----3---- e--------------------------
Ok, yeah, so we already saw this in a prior lesson. Well let's switch some chords to parallels with the same harmonic function:
fig 2 Am Dm/A G/B C vi ii V I e--0-----1------3-----0---- b--1-----3------0-----1---- g--2-----2------0-----0---- d--2-----0------0-----2---- a--0-----0------2-----3---- e--------------------------
fig 3 Am F/A Em/B C vi IV iii I e--0-----1------0-----0---- b--1-----1------0-----1---- g--2-----2------0-----0---- d--2-----3------2-----2---- a--0-----0------2-----3---- e--------------------------
Those are a bit different, but they all seem to "push" in the same direction, right?
So if all these chords fall into these functions and each one leads into the next one, how do we compose? It may feel like these rules are locking us inside a cage where we can make a substitution here and there but aren't really free to branch out. Here are several points to keep in mind:
- We are only using diatonic chords.
- We are immediately moving from one function to the next, rather than hanging around and embellishing the function before moving on.
- We are confined to one key instead of modulating or borrowing from other keys.
- We haven't entertained the idea that we can ignore the functions described above.
- We are only looking at harmony, without any context of melody or rhythm. Even with all the points above, a seemingly simple progression can undertone a wide range of actual songs. Check out the "4 chord song" by Axis of Awesome.
Circle Progression
Another way to progress through chords is given to us by the circle of fifths. We haven't covered that yet, but we will soon. Essentially, it arranges notes in order of fifths, with each note being a perfect fifth higher than the previous note as we traverse the circle clockwise. Here's the notes from Cb to C# along the circle of fifths.
|------------------------------------------------| Cb - Gb - Db - Ab - Eb - Bb - F - C - G - D - A - E - B - F# - C#
Enharmonically, Gb and F# are the same pitch; so the circle is just repeating at that point, indicated by the range above the notes above.
If we use only diatonic notes for any particular major key, the 7th note does not have a diatonic perfect fifth but a diminished fifth. In C Major, B-F is a diminished fifth instead of a perfect fifth; however, we can still make the circle:
|-----------------------| F - C - G - D - A - E - B - F - C
We have already learned that the strongest harmonic resolution is from Dominant to Tonic (or V - I). The circle progression makes use of this - we simply traverse the circle counter-clockwise, using that note as the root of the next diatonic chord in the sequence. So in the key of C Major, a complete circle progression is:
C - F - Bdim - Em - Am - Dm - G - C I - IV - vii° - iii - vi - ii - V - I
We haven't talked about that Bdim chord yet, so let's leave it out. Let's also leave out the IV chord, since a IV - iii resolution may be a bit awkward. This leaves us with:
C Em Am Dm G C I iii vi ii V I e-0---0---0---1---3---0-- b-1---0---1---3---3---1-- g-0---0---2---2---0---0-- d-2---2---2---0---0---2-- a-3---2---0-------2---3-- e-----0-----------3------
Every chord leads into the next pretty seamlessly.
The circle progression gives us a basic roadmap of how to get from any chord to any other chord in the same key. Knowing harmonic function allows us to take "shortcuts" and jump some intermediate chords. For example, we know the harmonic function of IV is pre-dominant, so we can jump from IV to any dominant function chord. Let's choose V. That leaves us with I - IV ... - V - I. We're back to our basic I - IV - V - I example!
Sample Progression
Let's make up a song real quick. We will use the key of C Major (do we have a choice yet?) and want to start on the tonic. Let's add some rhythmic variety. We'll stay on the C Major chord for a full measure, which will help really establish the key of C Major. Then let's repeat the part of the circle progression again from iii to ii. We know that ii is a predominant function and iii can have a dominant (as well as tonic) function, so let's dwell on the ii for an extra beat, then go back to iii. From iii we circle progress again, but instead of stopping at ii, this time we'll keep going to V.
C Em Am Dm Em Am Dm G C I iii vi ii iii vi ii V I e-0-------------|-0---0---1------|-0---0---1---3-|-0---------- b-1-------------|-0---1---3------|-0---1---3---3-|-1---------- g-0-------------|-0---2---2------|-0---2---2---0-|-0---------- d-2-------------|-2---2---0------|-2---2---0---0-|-2---------- a-3-------------|-2---0----------|-2---0-------2-|-3---------- e---------------|-0--------------|-0-----------3-|------------
Play this nice and slow. You don't want to be jumping from chord to chord very quickly - it ruins the harmonic impact. Start at like 50 bpm. Most chord progressions dwell on each chord for a full measure. But without drums and a melody, that's a bit boring.
Bad Examples
Let's be bad and break the rules, just to see what happens...
C Dm Am Em F Am G Dm C G I ii vi iii IV vi V ii I V e-0-------------|-1---0---0------|-1---0---3---1---|-0------3------- b-1-------------|-3---1---0------|-1---1---3---3---|-1------3------- g-0-------------|-2---2---0------|-2---2---0---2---|-0------0------- d-2-------------|-0---2---2------|-3---2---0---0---|-2------0------- a-3-------------|-----0---2------|-----0---2-------|-3------2------- e---------------|---------0------|---------3-------|--------3-------
Here's the same example as above, but I've changed the order of a few chords, added the IV into the mix, and added a V as the last chord. Let's analyze what's going on.
Instead of the iii - vi - ii progression, we have the reverse. This is opposite the circle progression and should seem to slightly increase tension, but overall, it's not too bad. The chords ii and vi chords serve a predominant function, whereas the iii can serve as dominant.
The next measure is a bit crazier. We go from the held dominant-function iii to IV, the staple pre-dominant chord. This transition should be a bit odd. Then we move to the vi, which also has a predominant function, but is a bit weaker than the IV in this regard. In this respect it appears we are moving away from predominant and towards tonic (iii and vi have some tonic functionality). But then we go to the V chord, which is a bit unexpected and contrary to the last chord. From V, we go back to ii. This is a poor resolution - the tension already built should continue or even heighten.
From ii we go back to I. This is a very poor resolution, especially to the tonic. Much of the tension created will not be relieved, and even though we've reached the tonic chord, we won't feel like we've completed our musical journey. And then we progress to a final V chord. Remember that the dominant chord has the most tension to resolve to tonic. We never resolve it...
As bad as that example was, it's not that bad. Since all diatonic chords fit into one of 3 basic functions and the functions merely describe the interrelated tension, most progressions that exclusively use diatonic progressions and begin and end on the tonic should sound relatively good. Also, remember that tension itself is not bad. In fact it's good to keep things from being boring. Let's see about that:
C Am Em Em Am C I vi iii iii vi I e-0-------------|-0-------0------|-0-------0------|-0---------- b-1-------------|-1-------0------|-0-------1------|-1---------- g-0-------------|-2-------0------|-0-------2------|-0---------- d-2-------------|-2-------2------|-2-------2------|-2---------- a-3-------------|-0-------2------|-2-------0------|-3---------- e---------------|---------0------|-0--------------|------------
This progression uses only chords with some tonic functionality. And we begin and end on the tonic chord. We avoid any dominant to tonic resolution which could occur between iii and I. Is this progression wrong? No - it doesn't break any rules so to speak. It just doesn't have any strong tension or release. This can be desirable or not given the circumstances.
Well, how about a truly bad example then...
C Dm Em F G Am C I ii iii IV V vi I e-0------1------|-0------1-----|-3-------0------|-0---------- b-1------3------|-0------1-----|-3-------1------|-1---------- g-0------2------|-0------2-----|-0-------2------|-0---------- d-2------0------|-2------3-----|-0-------2------|-2---------- a-3-------------|-2------------|-2-------0------|-3---------- e---------------|-0------------|-3--------------|------------
Here, we are simply ascending the C Major scale, with each note used as the root of the next chord in the sequence: C Dm Em F G Am. ii has a predominant function, so it's no so bad that it leads into iii, but this implies the iii has a dominant function. The next chord is IV, the main pre-dominant chord. iii - IV might work if the iii has a tonic function, but in this case it doesn't; and the transition will sound awkward. IV - V is common and worry-free progression, but the following V - vi hurts the dominant functionality of the V. Even though vi can have tonic functionality, it is much less strong than the V - I, dominant - tonic resolution. Then we have vi - I. The vi likely serves a tonic functionality here, coming off the preceding V. This makes the vi - I progression weak and uneventful, probably the opposite of what is desired leading into the last chord of the piece.
Homework
Memorize the tables of chords and functions above. Play through all the progressions on this page, following the analysis of harmonic function or how it relates to the circle progression. Create at least 3 of your own progressions. Learn how to establish a key, create tension, and relieve it.