Articles - Guitar / Music Theory

Note: Before you look at this, make sure you know "The Most Basic Music Theory" & "Scales" found in the article page here.

Have you ever wondered how chords are constructed? Ever asked yourself "what does Aaug, F#m7, Dmaj7, Esus mean?" Well, here are the answers to your questions. In this set of notes, we'll explain to you the theory of chord construction.

The aim of this lesson is to help you to be able to figure out chords by yourself without always having to depend on the chord chart.

Let's start by using the C major scales and giving them numbers accordingly.

Note: There isn't really such a thing as an eighth (8) note. It's just the first (1) note repeated in the next higher octave.

4 main triads (3 notes chord)

So looking at the table above, you can tell a C chord is actually made up of 3 notes, that is C, E, G. So when we play on any instrument, as long as only this 3 note is present, it is a C chord. With C as the root note, that is in the bass note. Of course there is causes when C is not the root note, we call this inversion. We will discuss this on another topic.

Note: The chord C+ can be written as Caug too, and the chord Co can be written as Cdim.

The triads form the basis of the rest of the other chords to come.

Chords with Major triad base

Chords with Minor triad base

As seen above, all this chords are actually build upon the triad. Now can you see what does the number mean? It actually show you what note to put in looking at the C major scales.

For eg, the sixth note of the C major scale is (A), so a C6 will simply be the C major triad (C, E, G) plus the sixth note (A).

Of course this is only for the C major scale, with your knowledge of major scale, just number them accordingly starting from the root note.

D major scale is shown below

Example: D6 = 1, 3, 5, 6 of D major scale (because it is a D6, so use D major scale, not rocket science huh?)
So D, F#, A, B will be the notes forming the D6 chord.

Below is a exercise for you to do before we continue

Now that you have completed the above exercise. You should if you did not do it. If not done, do it now. Just do it. Come on, do it.

To make things easier, we will give you all the scales in the major key below.

Suspended

Note: A suspended chord means taking out the 3rd and replacing it with either a 2nd or 4th.

Note: Csus = Csus4

Chords above 7th

Note: Once you go above 7th, For chords like 9, 11 and 13. You are suppose to play all the notes from 7th and up in that chord.

Half Diminish

Diminish 7th / Full Diminish

Note: Although there are four different chords below, yet actually all of them are the same. However, the root note is change.

Below is another exercise for you to do

Note: A chord with “add” means that you add the number shown only, ignoring the rules for chords above 7th.

Now that you have knowledge of how chords work, we will continue on "Chord Construction Theory (2)" on how to apply this knowledge onto the guitar fretboard.

By Wui-Ping