Ch 3 Chord Synonyms and Substitutions

As you’ve seen from time to time in the first two chapters, some chords have exactly the same notes and guitar chord forms as another chord of a different name. For example, in Sections 1-4 and 2-4, you saw that C6 consists of the same notes (C-E-G-A) and shares the same chord forms as Am7 (A-C-E-G). Also, Sections 1-7 and 2-7 revealed that a diminished chord shares the same notes with, and is equivalent to, three other diminished chords of different roots that are a minor third apart.

Chords that have the same or similar structure but are called by different names are said to be synonyms. In such a case, the chords can be used interchangeably, or substituted for one another. Replacing one chord with another, or chord substitution, is very commonly done in jazz and other styles of music when composing or arranging a song. During the performance, a player may also spontaneously substitute chords on the spot. There are many benefits and advantages of learning the chord synonyms and substitutions. Some of them are:

l Adding extensions or alterations to a chord can often be easily done by substituting it with a chord you already know.

l Instead of learning a new chord shape, you can simply adapt the chord form you know.

l The fingerings can sometimes be simplified.

l Chord transitions can become smoother and easier.

l You’ll have more tools for arranging and adding interest to a song.

In Sections 3-1 to 3-3, you’ll first look at the three common types of chord substitutions: diatonic, tritone, and diminished. A chart of chord synonyms will be presented in Section 3-4, and Section 3-5 will list some examples of chord substitutions in the context of the II-V-I progression.

A good understanding of chord synonyms—or equivalent chords—will provide you with various choices and ideas that allow you to substitute chords freely and effectively. You may at first feel overwhelmed by the numbers of chord synonyms and endless possibilities. The important thing, however, is to digest one item of information at a time, gradually incorporate it into your own playing, and then experiment with other substitution ideas over time.

( from More Jazz Guitar Chords and Accompaniment)