So far, such pitch changes have been referred to as “intervals.” From now on, they’re melodic intervals, so as to distinguish them from harmonic intervals (chord changes). So, in the above example, there are five notes and four melodic intervals.

A succession of harmonic intervals (chord changes) is represented like this:

I – VIm – IIm – V7 – I

Each symbol represents a harmonic degree, commonly known as a chord. Each dash represents a harmonic change, from one chord to another chord.

Such harmonic changes are called harmonic intervals, or chord changes, or chord progressions. All of these terms mean the same thing. In the above example, there are five chords and four chord changes or harmonic intervals.

6.5.2

HOW CHORDS ACTUALLY CHANGE

When you play your guitar or keyboard and change chords, you do not necessarily go from one chord in its root position to another chord in its root position. Instead, you typically switch among roots and the various inversions.

Figure 44 below shows a typical chord progression, G – C – F.

• The top line shows the notes of the chord G major.

• The middle line shows the notes of the chord C major.

• The bottom line shows the notes of the chord F major.

The arrows show which notes of one chord are changing to which notes to form the next chord. The dark letters show the chord roots.

• Some chords have the same note in common. So there’s no change in these notes when the chords change.

• The first and last chords (G major and F major) are in root position (their root notes are furthest to the left) while the middle chord (C major) is a second inversion chord (the note G is in root position).

FIGURE 44 Typical Chord Changes: G Major (Root Position) to C Major (2nd Inversion) to F Major (Root Position)

So, a chord progression (such as the one above) is a movement of chords in their entirety, not merely a movement of notes, or chord roots, or specific inversions.

In fact, there’s no such thing as movement of “chord roots.”

In harmony, chord-to-chord movement is of an entirely different sort, compared with melodic note-to-note movement. It sounds different, it feels different, it is different.

As the chord changes from G major (top line in Figure 44) to C major (middle line) to F major (bottom line), it’s clear that the overall sound of the chord changes have nothing to do with rising or falling pitch.

As the chords change, the notes within the chords don’t move much in pitch. In four cases, the notes remain in exactly the same position as the chord changes. In most of the other eight cases, the pitch change from chord to chord is only a semitone or a tone—up, in some cases, down in others.

What your brain hears as the chords change in sequence are changes in musical “color,” not rising or falling pitch.

6.5.3

THE TRICKY BUSINESS OF NAMING HARMONIC INTERVALS (CHORD PROGRESSIONS)

Melodic intervals have logical, straightforward names (more or less). A perfect fourth is the interval between the tonic note and the fourth note of the diatonic scale. A perfect fifth is the interval between the tonic note and the fifth note of the diatonic scale.

Naming harmonic intervals (chords) is not so straightforward. Chord movements are named according to the intervals between their roots, even though root movement has no meaning by itself.

It’s the whole chord that moves, regardless of root or inversion. The chord is simply named after the root.

The tricky thing here is that the name of the interval between chord roots can have two meanings:

1. It can refer to the movement of a given chord “up” to the next chord in the progression, with respect to the root name—for example, C “up” to G if you go like this: C, D, E, F, G.

2. It can refer to the movement of a given chord “down” to the next chord from the original chord, with respect to the root name—for example, G “down” to C if you go like this: C, B, A, G.

Either way you figure it, you’re still changing from a “C” chord to a “G” chord. But the order of the chords in the progression matters with respect to naming. The chord change from C to G has a different name, and a different musical effect, compared with the chord change G to C.

6.5.4

FIFTH PROGRESSIONS, UP AND DOWN

As noted, harmonic intervals (chord changes) are named after their roots.

In Figure 45 below, you can see the dilemma. The root is just one of several notes in a chord. So how do you name these harmonic intervals?

• When you change from the chord G major to the chord C major, is that an interval of a fourth or a fifth?

• Is it going “up” or “down”?

• When you change from the chord C major to the chord G major, is that an interval of a fourth or a fifth?

• Is it going “up” or “down"?

FIGURE 45 Dilemma: How to Name These Harmonic Intervals (Chord Changes)

Since root movement by itself has no meaning in harmony, movement “up” or “down” from one chord to another chord amounts to exactly the same thing, with respect to root movement.

Recall the discussion of complementary intervals from Chapter 4. Any two intervals that add up to an octave are called complementary intervals. In harmony, complementary harmonic intervals have the same names, as you’ll see in a minute.

The harmonic interval (chord change) G – C spans the same harmonic distance as the harmonic interval (chord change) C – G. That’s pretty obvious: when you play the chords C – G – C – G – C – G, you’re just playing the same two chords alternately.

This is different from melody, because in melody, the octave matters. In melody, the interval C – G is a perfect fifth (with C as the lower pitch), but the interval G – C is a perfect fourth (with G as the lower pitch). So you hear two different melodic intervals:

C – G

G – C

or the ascending melodic sequence:

C – G – C

where the second C is an octave above the first C. Two distinct melodic intervals, three distinct pitches.

Not so in harmony.

You hear only one harmonic interval when you play the chords:

C – G

G – C

And when you play the harmonic sequence (chord progression):

C – G – C

you hear only two chords. The second C chord is exactly the same chord as the first C chord. The octave in which you play these chords does not matter. The two chords are both still either C major or G major chords.

And yet, despite the single harmonic interval, there is an important distinction between these two chord sequences:

C – G

G – C

In harmony, the distinction is that C – G is considered a harmonic movement “up” because you get to the root note of the next chord by going “forward” alphabetically from the root note of the first chord to the root note of the next one in the progression. Like this: C – D – E – F – G.

The progression G – C is considered a harmonic movement “down” because you get to the root note of the next chord by going “backward” alphabetically, from the root note of the first chord to the root note of the next one in the progression. Like this: G – F – E – D – C.

Unlike in melody, the harmonic terms “up” and “down” with respect to interval movements (chord changes) have nothing whatsoever to do with pitch change. Unlike in melody, the chord change G – C does not mean that the chord C is “higher” or “lower” in pitch than the chord G.

Chord Sickness and Barfing Audiences

Suppose you have $20 million burning a hole in your jeans. That’s what it costs to visit a space station as a tourist. (NASA is ready to take your order. Operators are standing by.)

Once you’re up there, the space station orbits in a certain direction. But inside the spacecraft, your body floats all over the place. You do not perceive your motion to be “up” or “down.” There’s no “up” or “down” in space. So you get space sickness and you barf. And your fellow astronauts move away from you and mutter to each other about how disgusting you are.

That’s how chord progressions work. Chords move, and, under certain circumstances, they move in a perceived direction. But they do not move “up” or “down,” the way melody does. There’s no “up” or “down” in harmony. So, if you don’t know what you’re doing when you create a chord progression, your listeners may get chord sickness and barf.

In harmony, both chord changes—the chord C moving to the chord G (thought of as going “up,” which means counting forward from the first chord: C, D, E, F, G), and the chord G moving to the chord C (thought of as going “down,” which means counting backward from the first chord to the next one in the progression: G, F, E, D, C), are called, by convention, fifth progressions. Even though, in terms of melodic scale degrees, G – C is a fourth.

So, unlike the situation with melodic intervals, you never refer to a chord change such as G – C as a harmonic interval of a fourth (a “fourth progression”). No such thing.

Figure 46 shows an example of how fifth progressions get their names. The chord change is from G major in root position (top line) to C major, second inversion (middle line) to F major in root position (bottom line), or the reverse, from F to C to G. Although all the notes change simultaneously as you move from line to line, the arrows show only the chord roots (after which the chords are named).

FIGURE 46 Fifth Progressions, Up and Down

To summarize:

1. If you go from the top line to the bottom line, the chords change from G major to C major to F major. These are called fifth progressions, down (counting backward from the first chord root to the next one in the progression).

This is a fifth down chord progression:

G – C – F

2. If you go from the bottom line to the top line, the chords change from F major to C major to G major. These are fifth progressions, up (counting forward from the first chord root to the next one).

This is a fifth up chord progression:

F – C – G

When you play these two chord progressions, they sound quite different from each other. That is, a fifth down progression has a different harmonic character from a fifth up progression. Even though both progressions consist of exactly the same three chords. Even though the notes within each chord are identical.

The sequence of the chords matters. That’s what gives each type of progression its own distinctive character.

It’s worth repeating that the terms “fifth up” and “fifth down” do not imply pitch change. The terms “up” and “down” are simply unfortunate quirks of nomenclature.

• “Up” means counting forward in letter-sequence order to arrive at the name of the next chord in the sequence (which is named for its root).

• “Down” means counting backward in letter-sequence order to arrive at the name of the next chord (which is named for its root).

Pitch is the “height” dimension of sound, so “up” and “down” make sense. Harmony is the “depth” and “color” dimension of sound, so using the terms “up” and “down” do not make sense. However, we’re stuck with the “up” and “down” nomenclature with respect to chord progressions, even though it’s completely misleading.

If you get confused about how chord progressions are named, just remember that "up” in chord progression terms means counting forward from the first chord-root name to the next one, and "down” means counting backward from the first chord-root name to the next one. (Nothing whatsoever to do with “up” in pitch or “down” in pitch.) Here are a few examples:

Count the fifth up, A – E , by reading forward: A > B > C > D > E

Count the fifth down, E – A , by reading backward: A < B < C < D < E

Count the fifth up, D – A , by reading forward: D > E > F > G > A

Count the fifth down, A – D, by reading backward: D < E < F < G < A

6.5.5

THIRD PROGRESSIONS, UP AND DOWN

Just as harmonic progressions with roots a fifth or a fourth apart span the same harmonic space, so harmonic progressions with roots either a third (e.g., Am – C) or sixth (C – Am) apart span the same harmonic space.

By convention, these are both called third progressions. And again, unlike the situation with melodic intervals, by convention, there’s no such thing as a harmonic interval called a sixth (a “sixth progression”).

• A third progression up means counting forward by letter-name from the first chord root to the next one in the progression. So Am – C is a third progression up.

• A third progression down means counting backward by letter-name from the first chord root to the next one in the progression. So C – Am is a third progression down.

Even though the same two chords are used, the sequence of chords matters. The progression Am – C sounds different from the progression C – Am. Just as a fifth progression up sounds different from a fifth progression down, so a third progression up sounds different from a third progression down.

6.5.6

SECOND PROGRESSIONS, UP AND DOWN

Harmonic movements with roots either a second (e.g., C – Dm) or seventh (Dm – C) apart span the same harmonic space, because there's no "up" and "down" in harmonic space, the way there is in melodic space (high pitch vs low pitch).

By convention, they’re both called second progressions. There’s no such thing as a harmonic interval called a seventh (a “seventh progression”).

• A second progression up means counting forward by letter name from the first chord to the next one in the progression. So C – Dm is a second progression up.

• A second progression down means counting backward from the first chord in the progression. So Dm – C is a second progression down.

6.5.7

CHROMATIC PROGRESSIONS, EXITING AND RETURNING

Diatonic harmonic intervals for a given key can only arise from triads built on roots belonging to the diatonic scale.

Why is this?

• The tonic note of a scale contains overtones that strongly reinforce scale degrees 1, 3 and 5. (Music always gets back to the brain recognizing simple-ratio overtones.)

• This in turn gives rise to the triad built on the tonic note, consisting of scale degrees 1, 3, and 5 of the diatonic scale, the overtones of which all reinforce each other internally.

• This gives rise to triads built on the other six notes of the diatonic scale.

• This provides a basic vocabulary of seven triads (three major, three minor, one diminished) in any given key, each with root-third-fifth structure and overtones all reinforcing each other.

• The brain interprets and processes all of these simultaneously-sounding tones with reinforcing overtones as the sonic delight, harmony.

However, chords can also progress by non-diatonic intervals—intervals whose roots are not in the diatonic scale of the prevailing key. Such chord changes are called chromatic progressions.

For example, in the key of C major, you would call the progression from the chord C major to the chord to E♭ major a chromatic progression.

Why not call this a third progression? After all, the root moves three semitones, just like the chord progression C – Am, a third progression. Why call C – E♭ a chromatic progression instead of a third progression?

Because in harmony, all three of the notes that make up each triad must belong to the diatonic scale for the prevailing key. Otherwise, there’s no tone/overtone acoustic resonance. Your brain simply does not recognize the chord as belonging to the prevailing key. The chord E♭ is therefore chromatic.

The chord E♭ major consists of the notes E♭, G, and B♭. If the prevailing key is C major, your brain does not recognize the chord E♭ major, with its chromatic notes E♭ and B♭, as belonging to the prevailing key.

Since chromatic chords have roots outside of the key’s scale notes, harmonic movement “up”or “down” (such as a “fifth up” or a “third down”) does not apply to chromatic chords. Instead, chromatic chord movement is defined as:

• Exiting the prevailing key when the progression moves from a chord within the key to a chromatic chord, and

• Returning to the prevailing key when the progression moves from the chromatic chord back to the key.

6.5.8

SUMMARY AND EXAMPLES OF THE FOUR TYPES OF CHORD PROGRESSIONS

Table 42 summarizes the only four harmonic interval (chord progression) types:

• Seconds (up or down),

• Thirds (up or down),

• Fifths (up or down),

• Chromatic (exiting or returning).

Keep in mind that the intervals in the “Examples” column are chord movements, not single note movements.

TABLE 42 The Four Types of Harmonic Intervals (Chord Progressions)

Root Movement

A Few Examples: Key of C / Am

Progression Name

SECOND PROGRESSIONS

I – II

II – I

VII – I

I – VII

C – Dm

Dm – C

Bº – C

C – Bº

Second progression, up

Second progression, down

Second progression, up

Second progression, down

THIRD PROGRESSIONS

I – III

III – I

VI – I

I – VI

C – Em

Em – C

Am – C

C – Am

Third progression, up

Third progression, down

Third progression, up

Third progression, down

FIFTH PROGRESSIONS

I – V

V – I

IV – I

I – IV

C – G

G – C

F – C

C – F

Fifth progression, up

Fifth progression, down

Fifth progression, up

Fifth progression, down

CHROMATIC PROGRESSIONS

I – ♭II

♭II – I

I – ♭III

♭III – I

I – ♯IV

♯IV – I

I – ♭VI

♭VI – I

I – ♭VII

♭VII – I

C – D♭

D♭ – C

C – E♭

E♭ – C

C – F♯

F♯ – C

C – A♭

A♭ – C

C – B♭

B♭ – C

Chromatic progression, exiting