Jazz Theory and Practice Module 2, a,b,c

Dominant-7th, Added-6th and Minor-7th Chords, The (II � V � I) progression

A. The Dominant-7th Chord.

a. Basic Structure of the Dominant-7th. You may already know that “dominant” usually refers to the

fifth step of the scale. When we refer to a “dominant-7th chord”, however, it might be built on any note, not just the

dominant note of the scale. When we use this term we are always referring to a unique harmonic structure that can be

figured out in different ways: (1) A major triad with a minor-7th above the root.

(2) A major third followed by two minor thirds above the root.

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b. Relationship to the major scale family.

In the major scale (Ionian Mode), we can add a seventh to all the chords in the scale, but only one of them becomes a

dominant-7th chord (the one on the dominant, or 5th step, of the scale).

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All the other chords are other kinds of seventh chords, mostly

major-7th and minor-7th chords, as we’ll discover later.

Copyright © 2012 Peter J. Clements

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When chromatic notes (notes outside the scale) are used,

dominant-7th chords can be found on other notes of the scale in almost any jazz or pop song:

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In the mixolydian scale, a dominant-7th chord can be built on the first note of the scale, and jazz musicians often use the

mixolydian scale to “fill in” an improvisation over a dominant-7th chord:

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c. Resolving dissonance; voicing.

In the study of traditional harmony there is a great deal of

attention paid to the resolution of the dominant-7th. Resolution means that the third of the chord usually rises a

half-step, and the seventh usually falls, either by half- or whole-step. Depending on the harmony textbook, there are

various rules and exceptions, but they all come back to resolving the third and the seventh of the chord. The third

is usually a leading tone, and “leads” or pulls strongly to the next note above, and the seventh has an opposite pull

downwards. These two notes together form a dissonant interval: either a diminished fifth or an augmented fourth.

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If you play both of these intervals on the keyboard you will

discover that they sound the same, and actually have the same distance between the notes: three whole steps (tones),

even though one of the whole steps appears as a diminished third within the diminished fifth. Based on the three whole

steps, we use a common name for both intervals: the tritone.

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For simple harmonic progressions, where a dominant-7th

chord moves to a basic triad with the root a perfect fourth above, and occasionally a second (major or minor) above, the

most natural and anticipated movement of the voices (resolution) would be with the third of the chord rising, and

the seventh falling. Study the following examples carefully:

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In these examples you will notice that, in order to resolve the parts smoothly, the fifth is often missing from a chord; if you

listen carefully you will discover that the ear hardly notices any difference. A common exception to the third resolution is

when the dominant-7th chord moves to another 7th chord (which happens often!). In this case, the third usually moves

to the 7th of the next chord:

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A common misconception about jazz harmony is that it is always full of thick chords with many notes. Most beginning

keyboard players think that a seventh chord must always have four different notes, a ninth chord must always have five

different notes, and so on. In actual practice, much of the musicality in jazz performance— whether it’s solo keyboard,

an arrangement for voices or instruments, or improvisation—

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comes from the voicing of the harmony, especially where

fewer voices are used to suggest a complex chord. As we’ve already seen in the two previous examples, the fifth of the

chord is often omitted, and is hardly missed by the ear. Look at the following example, and, in particular, the voicing in the

right hand:

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The first and third chords (E7 and D7) have no fifth in the

right hand, and the second and fourth chords (A7 and G7) have no root in the right hand. If you imagine a bass

instrument playing the left-hand part, the right-hand part could be the entire keyboard part, or an arrangement for

three saxes or three trumpets:

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The 3-part voicing can be reduced further, to only two voices, and the basic character of the dominant-7th chord is still

present, because the two active notes, the notes that form the tritone, are still there!

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The following example uses tritones in the left hand wherever there is a dominant-7th chord. (You will also find a longer

version in the “Play/Sing” section to follow.) You will

discover that the combination of the very “thin” left hand part, combined with other notes of the chord that emerge

from the melody produce harmony that sounds quite complete.

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Something to listen to: There are many pieces in the pop/jazz repertoire that use strings of dominant-7ths.

Perhaps the best-known example is Sweet Georgia Brown (Harlem Globetrotters theme song). It’s been played/sung by

just about everyone; for two contrasting performances find the one by Django Reinhardt, and the one by Count Basie.

Another classic piece that opens with a string of dominant-

7ths is Spinning Wheel. The definitive performance is the

classic rock group “Blood, Sweat, and Tears”.

Return to the menu, and try the PLAY/SING and WRITE

exercises for Module 2a.