This is the second article of a two-part series on modes. Last month, I explained how these scales are constructed; this month, we'll look at how they're used to make music. If you're new to these concepts, please refer to Part 1 so you understand the information that follows.

First, some terminology. Rather than use the "do, re, mi" labels for the Major scale pitches, I'll use Roman numerals: do = I; re = II, mi = III, fa = IV, so = V, la = VI, ti = VII, and do = I again.

As we saw last time, each pitch (or "degree") of the Major scale has a mode: I = Ionian, II = Dorian, III = Phrygian, IV = Lydian, V = Mixolydian, VI = Aoelian, VII = Locrian. As it turns out, there's a chord for each degree as well. That is, if you build a triad or 7th chord up from each scale degree, you get a specific chord for each one. The triads are: I = Major, II = minor, III = minor, IV = Major, V = Major, VI = minor, VII = diminished. The 7th chords are: I = Maj7, II = min7, III = min7, IV = Maj7, V = dom7, VI = min7, VII = min7flat5. Since these chords are built on — and out of — scale tones, they're called "scale tone chords."

What this means is that certain types of chords and certain modes "go together." For example, the V is a dom7 chord, and its corresponding mode is Mixolydian. In practical terms, when you encounter a dom7 chord in "real life," you can often play over it using the Mixolydian mode (e.g. D7 chord = D Mixolydian scale).

Let's see this principle at work with a common chord vamp — Amin7 D7 — repeating over and over, one measure per chord (this is the vamp from Tito Puente's "Oye Como Va," made famous by Santana). Again, the principle is that each type of chord has a corresponding mode. In the preceding paragraph, we saw that dom7 chords take the Mixolydian mode, so we can use D Mixolydian to play over D7 (D Mixolydian is: D, E, F#, G, A, B, C, D).

What about the Amin7 chord? Here, we have three choices, because (referring to the scale tone chords listed above) the min7 chord appears three times: on II, III, and VI. This means that the II, III, and VI modes (Dorian, Phrygian, and Aeolian) are all candidates for the Amin7 chord. What's the best choice?

In order to decide, let's see how they compare:

A Dorian: A, B, C, D, E, F#, G, A
A Phrygian: A, B-flat, C, D, E, F, G, A
A Aeolian (aka "Natural Minor" scale): A, B, C, D, E, F, G, A

Pick the A mode with the most tones in common with D Mixolydian, because this creates the smoothest transition. Again, D Mixolydian is: D, E, F#, G, A, B, C, D.

If you picked A Dorian, you're right. In fact, A Dorian and D Mixolydian are entirely composed of common tones, so they work perfectly together. If you used A Phrygian or A Aeolian, it wouldn't be "wrong" necessarily — you have complete freedom to play what you like. But the effect would be more disjointed, which most listeners would perceive as "wrong." If you want this effect, fine; if you don't, A Dorian is the "right" choice.

Some of you may say, "Of course A Dorian and D Mixolydian work together — they're both in the key of G." Yes, you could think of the vamp as a II V progression in the key of G. But it's not truly "in the key of G" because our home base is Amin7, not G. In fact, if you did play a G chord in this context, it wouldn't sound like a resolution at all. So, if Amin7 is home, are we in in the key of A minor? No, because the key of A minor has an F natural in it, and our modes both have F# in them.

So what key are we in? Actually, we're not in a key at all, even though our chords and modes all fit within the key signature of G Major. Instead, this vamp is called a "modal" progression, because its center of gravity doesn't coincide with that of a traditional Major or minor key signature.

Let's look at another modal progression, this time using triads: CMaj AMaj. Vamp as before, one measure per chord (this is the beginning of the song, "Easy to Be Hard," from the musical, "Hair"). Looking at the scale tone triads above, we see that three of them are Maj: I, IV, and V. This gives us three possible modes for each Maj triad: Ionian, Lydian, and Mixolydian (the modes for I, IV, and V). Our choices for CMaj are:

C Ionian: C, D, E, F, G, A, B, C
C Lydian: C, D, E, F#, G, A, B, C
C Mixolydian: C, D, E, F, G, A, B-flat, C

And for AMaj:

A Ionian: A, B, C#, D, E, F#, G#, A
A Lydian: A, B, C#, D#, E, F#, G#, A
A Mixolydian: A, B, C#, D, E, F#, G, A

Compare the scales in the two groups and choose the C mode and A mode that have the most tones in common with each other.

If you picked C Lydian and A Mixolydian, you're "right." C Lydian has an F#, which fits well with all three A modes, and A Mixolydian has a G natural in it, which matches all three C modes. Play these modes on your instrument and listen to how they complement each other.

Again, you could choose a different combination, but most people would hear it as "wrong," or at least surprising, because of the increased number of non-common tones. As a composer and player, it's your call, but choose consciously based on the effect you want to create.

This is a modal progression because its tonality is dependent on modes rather than a Major or minor key. In fact, as it turns out, there is no key that contains both of these chords. Even though it's a relatively simple progression, a beginning improviser would find it puzzling. Modes are the solution to the puzzle.

Modal progressions are quite common, in everything from contemporary jazz to old-time fiddle tunes. In fact, modal harmony is a staple of musical traditions from all over the world because its slightly "unresolved" nature is inherently interesting and energetic, even exciting. It takes time to memorize the modes and learn how to use them. But once you do, they become a valuable part of your musical vocabulary, allowing you to make sense of otherwise confusing musical situations. Enjoy!


Copyright 2002 by Richard Middleton.
All rights reserved.