Major Scale Chord Function: How Chords Behave

Why Do Chord Progressions Sound Good?

Why do some chord progressions always sound good, while others sound stale? The way chords interact is a result of each chord’s function. If a chord fulfills its function, the resolution is satisfying. If a chord does not fulfill its function, the effect can be surprising. If chord progressions are written without understanding function, the results are erratic. Sometimes, a hit song is born. Most of the time, though, the chords just won’t sound very good.

C Major Scale

C Major Chords

Chord Function

Music has no real rules, except those of perception. In art, it’s a rule that black and white contrast well, while orange and yellow contrast poorly. It’s up to the artist to use this information to create.

How can we classify the “function” of these chords? We can start in the obvious place: the first chord. This chord is built on the first note of the major scale, and is called the tonic chord. This chord is often the first chord in a song as well as the last. It has a sense of restfulness.

We can classify the other chords based on how they relate to the tonic. We’ll find that there are essentially three types of chord functions, based on what tones the chords contain.

Naming the Chords

For this, we’ll need a system for naming these chords that describes their relationships rather than their notes. That way our research is useful no matter what key we’re in. We’ll use a system of Roman numerals. The chords will be labeled I, ii, iii, IV, V, vi and vii˚. Major chords are capitalized and minor chords are lower-case. The diminished chord has a special symbol indicating that it is diminished.

Tension and Release

In our major scale, we have two notes that are half steps away from another. These notes are F and B. Because of the conflict between these notes and the tonic notes they are a half step apart from, these notes are like “aliens”. They come to visit, but they don’t belong and can’t stay forever.

In tonal harmony, the tonic chord (“I”) has a sound that makes us feel like we’re at home. The other chords have a function determined by how far away from home base that chord is. The two notes that are furthest from home base are the aliens: F and B. A chord’s function is largely determined by how much “F” and “B” it has in it, with the chords that pull “out” the most having both and the chords that pull “in” the most having neither.

Chord Functions in Major Keys

Tonic Chords: I, iii-, vi-

A tonic chord contains the stable third of the key and at least one other note from the I chord. Clearly the I chord is a tonic chord, but so is the third chord: E- contains the tones E and G, both from the tonic chord. A- contains the third as well as the tonic note itself. Both of these chords sound similar to the tonic chord. We’ll call the three chord iii-, the lowercase numerals and minus sign indicating that it is a minor chord. We’ll call the six chord vi-.

Subdominant Chords: IV, ii-

The subdominant chords both contain the note “F”, significant because that note creates a gravitational pull away from the tonic chord. They also both do not contain the tone “B”, which is a strong tone that tends to create the expectation of resolving up to C. These chords have a stronger pull than tonic chords, but a less-stronger pull than dominant chords. When one of these chords appears, it is possible that a dominant chord is approaching; however, sometimes a subdominant chord will appear and then return to the tonic. These chords are stable enough to go almost anywhere. This is especially true of the IV chord, which often resolves back to I without a dominant chord.

Dominant Chords: V⁷, vii˚

Both of these chords contain the tones “F” and “B”, and therefore have the maximum amount of conflict and tension. These two tones want to resolve to the tones “E” and “C” respectively, tones in the tonic chord. This expectation is the reason why the chord will often be followed by a tonic, which will contain the expected notes and complete the resolution. The V chord is used much more often than the vii˚ chord is, for reasons we won’t explore here.

Knowledge of chord function is powerless without understanding how it sounds!

Play through different chord progressions and observe the effect of the tonic, subdominant, and dominant chords. If you need something to start with, try this list of four-chord progressions.

Key Questions:

1. Which chords are “tonic chords”?
2. Of the tonic chords, which chord is the most substantial?
3. Which chords are the “subdominant” chords?
4. Which chords are the “dominant” chords?
5. Of the dominant chords, which is the most substantial?
6. A subdominant chord tends to move towards a ______________ chord.
7. A dominant chord tends to move towards a ______________ chord.