The Nashville number system is one of the most powerful musical tools you can have in your arsenal as a worship musician. It allows you to transpose songs between different keys, learn songs by ear, and quickly communicate with other musicians.

How does it work?

1 | Song key

The song key is the starting point. Once you know the song key, you can figure out everything from there. The Nashville Number system is built on scale degrees (in a scale, each note gets a number.) Take the C Major scale for example. It would look like this with scale degrees written with it: 1 - C, 2 - D, 3 - E, 4 - F, 5 - G, 6 - A, 7 - B. Every note of the scale has a number associated with it.

2 | The Numbers

Now that you know the scale degrees you can build chords from those numbers. This is where the term the 1 chord, the 4 chord, the 5 chord, and the 6 chord come from. Each chord is based on the corresponding scale degree. For example, the 1 chord in the key of C is C (the first degree of the scale.) The 4 chord would be an F (the fourth degree of the scale.) And so on. The only other part you have to worry about is whether the chords are major, minor or diminished. This follows a standard pattern in major keys.

1 - Major, 2 - minor, 3 - minor, 4 - Major, 5 - Major, 6 - minor, 7 - diminished.

3 | Transposition

Once you know the number of chords, you can easily transpose between keys by matching up the scale degrees from one key with another and interchanging the corresponding chords. For example, this is the D scale: 1 - D, 2 - E, 3 - F#, 4 - G, 5 - A, 6 - B, 7 - C#.

Let's say you want to take a song in the key of C that uses the chord progression C, G, F and put it in the key of D. First, you would find the scale degree of each of those chords (1, 5, 4). Then match those scale degrees up with the D scale degrees. You'd find out that the 1, 5, and 4 chords in the key of D are D, A, G.