The Nashville number system allows you to quickly jump into unfamiliar music even without knowing standard notation! As the name suggests, it originated with Nashville studio musicians who needed a quick and easy way to transcribe songs and to modulate seamlessly between keys. By learning the system of roman numerals, you can jump into a jam situation with the confidence of knowing the basic structure of the song.
If we look at the chords of a diatonic key, they follow the same root notes as the major scale from which they were derived. In total, there are 7 basic chords that we will apply this system to. They always follow this basic principle:
Major, minor, minor, major, major, minor, diminished.
or you could think of it in terms of steps and half-steps on the guitar:
Whole, whole, half, whole, whole, whole, half.
simplified even further, the number of frets you move:
In C Major, it would look like this:
CMaj, Dm, Em, F, G, Am Bdim.
These are the seven basic chords which we are going to work with for now. In the next video, we will begin to apply the Nashville system of numbering to the diatonic chords we now know.