I've recently learned of a system developed by a guitar teacher and a VI guitarist that describes chords with a six digit code. This code works for every chord, or note on the guitar!
I made up a system similar to this for a VI student of mine several years ago, but never developed it like these two have.
Here's how it works:
The six strings of the guitar have always been numbered from the bottom string up - #1, the highest sounding string, is on the bottom of the neck. #6, the lowest sounding string, is at the top of the neck.
Now get a mental picture of the neck. Count the strings from the top down - 6,5,4,3,2,1.
The frets are also numbered - open (nothing pressed down) is 0. Then first fret, 1, second fret, 2, third fret, 3, and so on.
A common chord like G major uses three fingers - your third finger goes on the sixth string at the third fret. Your second finger goes on the fifth string at the second fret. Your fourth finger (pinky) goes on the first string at the third fret. The strings in between don't get any fingers, so when you strum, they are "open".
The six digit code is always given from the sixth string to the first.
So, for a "G" chord, the code is 320003.
Third fret, second fret, open, open, open, third fret. Make sense?
A "C" chord would be X32010.
The X means that you don't use that string in the chord, so when you strum, try to leave that one out.
A "D7" chord would be XX0212.
Any chord can be designated this way!
This is an exciting development for people who can't see chord diagrams on a page of music! And I believe that chord lists could be set up for a computer reader that would say the code when the letter name is pressed on the keyboard.
I will post again, when I have more info!
Have a Good Day!