The Nashville Number System (NNS) is a way of writing music with numbers rather than the letters traditionally found in music notation. The benefit to the NNS is that you can have one sheet of music and use it to play a song in any and key. Another benefit would be between two guitar players playing the same song but one is using a capo. They can call out the same numbers to each other even though they would be using different chord shapes. The NNS takes more work initially to memorize, but once you’ve done you homework I promise you won’t regret having learned it.
1) Numbers (ex. 1, 2, 3, 4, 5, 6, and 7) represent the scale degrees
Example: Key of G – G=1, A=2, B=3, C=4, D=5, E=6, F#=7.
Example: Key of A – A=1, B=2, C#=3, D=4, E=5, F#=6, G#=7.
2) In major scales your 2, 3, and 6 chords will always be your minor chords. The 6 is typically your most common (AKA relative) minor chord.
3) A lowercase “m” after a number represents a minor chord.
4) Chords joined with a “/” symbol represent a main chord with a different bass note.
The first chord is the main chord, the second chord is the bass note.
(example. 1/3 : 1 is the main chord, 3 is the bass note)
(example. 5/7 : 5 is the main chord, 7 is the bass note)
The key to mastering the NNS is knowing your scales in every key that you play in.
Check out this cheat sheet to make the learning process much easier:
NASHVILLE NUMBER SYSTEM PDF
Check out this example of “Freedom is Here” written with the NNS:
Freedom is Here – NNS
If we play “Freedom is Here” in the key of ‘G’ then in the key of ‘G’:
1 = G, 2m = Am, 4 = C, 5 = D, 6m = Em.