17th January 2022

In Nashville, the home of the Country Music recording industry, from the late 1950s onwards musicians developed a way of creating chord charts using numbers instead of chord names.

The numbers were based upon the position in the major scale of each chord. So if we were in the key of C, then C would be 1 (C being the first note in the scale of C major). D would be 2, E would be 3, and so on. You could think of these numbers as an alternative to the Italian ‘Do Re Mi’ words we sometimes hear.

Nashville numerical notation 1 2 3 4 5 6 7

So-Fa names/Solfège Do Ré Mi Fa So La Ti

Common musical notation C D E F G A B

To indicate minor chords, either an ‘m’ or a ‘-‘ (minus sign) may be used. For the purposes of this blog I am going to use ‘m’ as I think it is clearer.

Also, a further number may be used for an added note (e.g. a 7^th or a 6^th).

So in the key of C, A minor would be shown as ‘6m’, and G seventh would be shown as ’57’ (the modification, in this case 7, would often be shown in superscript, like this: 5⁷).

As an example, the chords C F G7 Am

would be written 1 4 5⁷ 6m

So much for the basic concept, but why did they develop this system?

The main reason is so that they could change the key of a song quickly, without having to write out the chart again! The composer may have written it in one key, but the singer says ‘can we take it up a bit?’.

I have already mentioned this type of situation in my blog about Capos. However, while that may work in some situations for a guitar player, it’s no help for a pianist or a double-bassist, as you can’t get capos for those instruments!

With numbering systems, experienced musicians who are used to transposing in their heads can just play from the numbered chord chart in a different key.

They will know that the ‘4’ chord in the key of C is F, and in the key of D it is G.

I should also mention that there is another numbering system based on Roman numerals. The number is shown in upper case for major chords and lower case for minor chords, with any modifications such as 7ths being shown as standard numbers.

So in the key of C, F major would be ‘IV’ and F minor would be ‘iv’, G7 would be ‘V7’ and Gm7 would be ‘v7’.

As far as I can see, there is no clear advantage to either system in preference to the other, although I think the Nashville system is a little easier to grasp. So I’ll stick with that, and not spend any more time on the Roman system.

Using numbers to refer to chords and to explain the structure of songs is pretty common. However, sometimes music theorists use words and phrases for chord relationships such as ‘Tonic’, ‘Dominant’ and ‘Sub-Dominant’. These are really just another way of using chord numbers!

Here are some of the words and phrases you may hear, followed by their Nashville equivalents, and the actual chords in the key of C

Tonic 1 C

Secondary Dominant 2 D

Sub-Dominant Relative Minor 2m Dm

Dominant Relative Minor 3m Em

Sub-Dominant 4 F

Dominant 5 G

Relative Minor 6m Am

Minor Keys

In the Nashville system, minor keys were usually treated as if they had been written in the related major key. So if a song is in the key of E minor, E minor will be ‘6m’, because E is the 6^th note of the scale of G major, the related major chord to E minor.

So a song that goes: Em Am D Em

would be numbered as: 6m 2m 5 6m

Matt G, 17/01/2022