Welcome to the Nashville number system lesson! This system has been used by many musicians across the world and should be part of your musical knowledge too.

In order to understand how the system works, we need to be comfortable with the harmonization of a Major scale. Let's work in the key of A Major and create chords starting from each one of the scale's notes.

We'll create four note chords using the root, 3rd, 5th and 7th of the scale as follow:

A Major scale:
A-B-C#-D-E-F#-G#

Chord 1 Maj7

(A-C#-E-G#)

Chord 2 min7

(B-D-F#-A)

Chord 3 min7

(C#-E-G#-B)

Chord 4 Maj7

(D-F#-A-C#)

Chord 5 7

(E-G#-B-D)

Chord 6 min7

(F#-A-C#-E)

Chord 7 min7(b5)

(G#-B-D-F#)

Because of the fact that the formula for a Major scale always stays the same, we will find the same types of chords no matter what key we work in. In other words, the 1st chord of a major scale will always be Maj7, the second chord will always be min7, and so forth.

Whenever writing a chart with that system, we'll use roman numbers. We'll use Capital numbers for Major chords and regular letters for minor chords.

We can now replace a chord progression like Bmin7-E7-AMaj7 by ii-V-I

Following are the fingerings corresponding to the placement of these numbers within the scale followed by some suggested chord positions.