Basic Triadic Harmony - Chord Scales
Today we're going to be thinking about triadic harmony and the chords in the key of A Major. Specifically the chords that make up the "chord scale". (All the chords in sequence built on every note of the scale) We won't use notation as in this theoretical context it's not really necessary.
Triadic harmony is a type of chord structure that consists of three notes: the root, the third, and the fifth. These three notes make up the basic triad of a chord. This is "basic" level harmony and is the building block of almost all popular music.
Further to my above point - since the guitar is a transposable instrument - if you know where each of the 7 tones of the major scale are/live on your guitar neck - you can simply use this "map" to create chords in any key.
Instead of "note names" you could simply swap out the note names for numbers - 1, 2, 3, 4, 5, 6, 7
In A Major, the chord scale is made up of chords built on the notes A, B, C#, D, E, F#, and G#. So, let's go through each chord in the key and see how they're constructed using triadic harmony.
The A Major chord is made up of the notes A, C#, and E.
The B Minor chord is made up of the notes B, D, and F#.
The C# Minor chord is made up of the notes C#, E, and G#.
The D Major chord is made up of the notes D, F#, and A.
The E Major chord is made up of the notes E, G#, and B.
The F# Minor chord is made up of the notes F#, A, and C#.
And finally, the G# Diminished chord is made up of the notes G#, B, and D.
So the chord scale for a major scale would look like this in "numbered" theory.
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
I hope this has been helpful and gives you a better understanding of how chords are built in a particular key.