Technique, Reading & Theory


Functional harmony, Roman numerals, Nashville numbers, and common chord progressions

Functional harmony

Functional harmony describes the relationship of each chord to the key center. Stacking thirds from each degree of the major scale creates seven chords within a given key. The key will determine whether each interval is a major or minor third. Analyzing these patterns will tell you whether you have a major, minor, or diminished chord. Let’s look at the key of C major:

functional harmony

Roman numerals & Nashville numbers

There are two common ways to notate chord function. The traditional (i.e. classical) method is to use Roman numerals: uppercase for major and lowercase for minor. Another common method is the Nashville Number System. This system uses Arabic numerals and chord symbols in place of Roman numerals but essentially works in the same way. These systems make it easier to learn songs or teach a chord progression to a fellow musician.

roman numerals and nashville numbers chord function

Common chord progressions

Most popular music uses the same chord progressions, or patterns, over and over in different keys. Practicing 1, 4, 5, and 6m chords in common guitar keys will help you advance as a guitarist and learn new songs quickly. Use the chart on the previous page for help finding these chords in some common guitar keys.

Common guitar keys:

After learning chord progressions in these common keys, we can transpose them to less common keys with barre chords or even with a capo.

These popular songs use 1, 4, 5, and 6m chords in different orders and combinations. This list is a starting point as these progressions are used in many styles of music. How many of these songs are you familiar with?

1 6m 4 5

1 4 5

1 5 6m 4

6m 4 1 5

6m 5 4 5

1 4 1 5

1 4 5 4

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