Now the question is which degrees of the scale comprise the chord, and the answer is:

• The First
• The Third
• The Fifth

So that’s the formula, easy huh?

Every chord by default comprises a first, third and fifth.

So lets discover this for ourselves.

Play the major scale as in the previous exercise.  As you play the major scale stop on the third and the fifth degrees.  You will discover that these are the notes that comprise the chord.

Q:  But how come a chord has only three notes and on the guitar we are playing more than three strings?

A:  They double up – or even triple up.  So a chord has only first thirds and fifths, however there can only be repeats.  So a C chord will have a first third and fifth, then another first and then another fifth. That’s how we get the four, five and six note chords.

Also it is interesting to study the order of notes.  They can be any order - as long as there are only first thirds and fifths.  It is this order that determines the character of the chord – the different orders are referred to as “chord voicings”.

Lets take the five open chords an examine how they are voiced.

C chord

I – III – V – I – III

G Chord

I – III – V – I – III – I

E chord

I – V – I – III – V – I

A chord

I – V- I – III – V

D chord

I – V – I – III

So now we have this information let’s see what we can derive from it.

It appears to me that the five open chords are in kinda two families.  That is the kind that has the lowest interval being a third, and the other with the lowest interval being a fifth.

So the chords with the fifth as the lowest interval are E, A and D.

The chords with the third as the lowest interval are C and G.

Notice there are two distinct sounds here.  The chords with the fifth as the lowest interval have a thick and rocky sound, this is the basis of much rock playing and including power chords.  The chords with the third as the lowest interval have a more open and jangly sound, great for acoustic and accompaniment.

Click here to learn the difference between major and minor chords