THE THREE CHORD TRICK
Let's start with the Major Scale--'C Major'
C D EF G A BC--Start on string 5, Fret 3
1 2 34 5 6 71
* The numbers are the notes of the scale, known as Tonic Degrees. By using them, we can find the famous Three Chords: 1, 4, 5. In C, that's C F G.
Okay, but why are these three the big, fancy "Primary Chords"? And who says so?
Not me--I'm just yore average plucker. It's the Rules of the Diatonic as laid down in the 17th century. The 3 Primary chords are Major; the other notes in the scale are roots of different chords. Think of the others as 'Support Chords'.
The Step Pattern
A Scale is built with 'bricks' called 2nds--gaps between the notes called Intervals.
A Major 2nd interval = 2 frets = a Tone---------------- A minor 2nd interval = 1 fret = 1/2 a Tone.
Scales have a pattern of full and 1/2 tones called a Step Pattern. In C Major, the step pattern is: