Music Theory

Making Chords from the Major Scale

A little on chords themselves: a major chord is made up of three notes, 1st 3rd 5th (from it's major scale). A minor chord changes slightly and is made up of 1st b3rd 5th (the 3rd is dropped by a fret). You can see this in any given open chord major and minor pairing.

That being the case, we can turn the notes of the major scale into full chords by taking each degree and finding its relative 3rd and 5th. Following that process we get:

1st - Major

2nd - Minor

3rd - Minor

4th - Major

5th - Major

6th - Minor

7th - Diminished

Therefore if we took the G Major Scale, the chords in the key of G Major would be: G Am Bm C D Em F#dim.

Just like in the scale, these chords would naturally resolve to the root (G). 

Some common major keys in songs: E, G, C, A, D

Harmonising Scales

You can harmonise a full scale just by using its notes to find the root, third and fifth of each degree. This involves a process of 'pick one, skip one, pick one, skip one, pick one'. For example, this is the process of harmonsing the major scale:

Major Scales Degrees: 1 2 3 4 5 6 7

C Major Scale: C D E F G A B

First Chord: Starts on first degree (i.e C).

C's 3rd and 5th (skip 2 and 4): E G

C E G = Major Triad

This means the first chord of a major scale is a major chord, in our example that's Cmaj.

Second Chord: Starts on second degree (i.e D).

D's 3rd and 5th in this scale (skipping 3 and 5): F A

D F A = Minor Triad

This means the second chord of a major scale is a minor chord. in our example, that's Dm.

If you did this for the rest of the major scale you would get:

1 = Major (1 3 5)

2 = Minor (2 4 6)

3 = Minor (3 5 7)

4 = Major (4 6 1)

5= Major (5 7 2)

6= Minor (6 1 3)

7 = Diminished (7 2 4)

So the chords of the C major scale are: C Dm Em F G Am Bdim 

MINOR SCALE

If you were to follow the same process for the C minor scale, this would be the result:

Minor Scale Degrees: 1 2 b3 4 5 b6 b7

C Minor Scale: C D Eb F G G# Bb

Minor Scale Chords: 

1 = Minor (1 b3 5)

2 = Diminished (2 4 b6)

b3 = Major (b3 5 b7)

4 = Minor (4 b6 1)

5 = Minor (5 b7 2)

b6 = Major (b6 1 b3)

b7 = Major (b7 2 4)

So the chords of the C minor scale are: Cm Ddmin Eb Fm Gm G# Bb

Relative Theory

As you may have noticed, when you look at the chord scale for the major and minor scale, the chords themselves are in the same order, just starting on a different note. That's due to relative theory. Every major key has a relative minor key, that is, a minor scale that contains all the same notes, and vice versa. Here's how:

C Major Scale Notes

 1   2   3   4   5  6   7

C  D  E  F  G  A  B

If you started that scale on the 6th degree you would get this:

6  7   1    2   3  4   5

A  B  C  D  E  F  G

Which actually is the A Minor Scale:

1   2  b3 4   5  b6 b7

A  B  C  D  E  F  G

You may also notice here that C, which was our root initially, is now the b3 of A Minor, and therein lies the relative theory basics:

The Sixth Degree of a major scale is the root of its Relative Minor

The b3 of a minor scale is the root of its Relative Major

That means both C major and A minor contain the same notes and chords, just in a different order as the root has been shifted. Here are all the relative Majors to Minor (of course, they also work the other way):

 

C Major - A Minor

C# Major - Bb Minor

D Major - B Minor

D# Major - C Minor

E Major - C# Minor

F Major - D Minor

F# Major - D# Minor

G Major - E Minor

G# Major - F Minor

A Major - F# Minor

Bb Major - G Minor

B Major - G# Minor

Seventh Chords

A Seventh Chord is created by adding another 3rd to an existing triad.

Major 7 = 1 3 5 7 (R M m M)

Minor 7 = 1 b3 5 b7 (R m M m)

Dom 7 = 1 3 5 b7 (R M m m)

Major Key 7th Harmony: Maj7, min7, min7, Maj7, Dom7, min7, m7b5

Minor Key 7th Harmony: min7, m7b5, Maj7, min7, min7, Maj7, Maj7