We call something a ‘Chord’ when 3 or more different notes sound out simultaniously, for instance G, B and D.
3 notes and each of them is different from the other.

Chords are derived from a scale.
Since we know different scales (Major, Minor, Mixolydian, …..) we’ll end up with all kinds of chords.

In the previous chapter we’ve seen that each scale is nothing more than a list of notes, stacked from low to high.
For instance: G, A, B, C, D, E, F# and G.
This scale has 7 different notes and devides the distance between two G’s that are an octave apart (12 frets).

A scale is defined by the distances between each of those notes.
If you list these distances in a row, you’ll end up with the scale ‘formula’.
For the G scale listed above the list of distances is:
2, 2, 1, 2, 2, 2, 1.
This is the formula of a major scale, in this case the G major scale.

Chords are built by taking a scale and using a mathematical formula.
This sounds very complex but really isn’t.

The simplest and most used chords use the formula 1 – 3 – 5.

This means that you start on the fist note of the scale, skip one, add the next, skip one and then add another.
For example: start one the first note of the G major scale : G
Skip one (A) and add the next: B
Skip one (C) and add the next: D

You end up with the notes G, B and D. This ends up being a G major chord.
It is ‘major’ and sounds major (= happy-ish), because of the interval between the first two notes of the chord: G and B.

The distance between these two notes (the first note of the scale and the third) is 4 frets or 4 x 1/2 note.
When this is the case the chord sounds ‘major’.
We call this distance a ‘major third’.

You can use the formula to create chords (1-3-5) starting on ANY note of ANY scale.
Because of the scale formula (2,2,1,2,2,2,1) you’ll end up with different types of chords.

When you do this on the G major scale, you could start on the second note A for instance.
Skip one (B) and add the next: C
Skip one (D) and add the next: E.

You end up with the notes A, C and E.

This ends up being a A minor chord.
It is ‘minor’ and sounds minor (= sad, depressed, melancholic), because of the interval between the first two notes of the chord: A and C.

The distance between these two notes (the second note of the scale and the fourth) is 3 frets or 3 x 1/2 note.
When this is the case the chord sounds ‘minor’.
We call this distance a ‘minor third’.

If we do this with ALL the notes from the G major scale, we end up with these chords:
G major, A minor, B minor, C major, D major, E minor and F# diminished.
Or abbreviated: G, Am, Bm, C, D, Em and F#dim.

Note: The F# diminished has an odd minor chord, that is not used a lot.
Because of this we’ll leave it for now and work with the first 6.