Nashville musicians have their own way of doing things, including reading music. When the little red light goes on in the recording studio, time is of the essence, and musicians that can work fast can work a lot. The “number system” is a sort of musical shorthand that makes learning, sharing, playing and transposing music a snap. Here’s the basic gist of it.
Every chord in a major scale has a number, based on where the chord letter falls in the scale. For example, in a C major scale, the notes are C-D-E-F-G-A-B. Translate the scale into chords and assign a number in order of ascension for each chord. C becomes “1,” the D chord is “2,” and so on.
If you are trying to communicate a minor chord, you will notate it with a dash (-) Notate Major 7ths with a triangle. Notate diminished chords with an O, (0) and augmented chords with a plus sign (+).
To notate time signatures and rhythm, write the value of beats per note in a section. If the number changes in a section, notate it, as well. Example: (1, ) (1,2 1), (1 4) You can use numbers for every beat, if you prefer. If you want to notate which beat goes with the chord change, do so by drawing an “i” underneath the beat.
Place bass note notation under the chord notation, with a line dividing them.
Write the numbers up and down or across the page, as desired, but make sure the handwriting is legible.
The Nashville number system is also helpful for singers and musicians working with big bands, as the conductor can communicate as the music is playing, letting the players know where to go with the music. To use the number system signals, make a dash movement with your hand, a triangle with your finger, an “O” with your hand and a upward or downward pointing fingers to indicate the number of sharps or flats in a key, as well as Major or minor chords.