Chord Construction
As mentioned in the previous lesson, chords are usually made up of combinations of major and minor third intervals. All of the chords you have learned up to this point have been triads (3 note chords). There are four basic types of triads: major, minor, augmented and diminished. Examples of each of these triads are shown here along with the formula for each one.
C Major Chord
C Minor Chord
C Augmented Chord
C Diminished Chord
By using the correct formulas, it is possible to build any of the four types of triads on any note of the chromatic scale. For example, if you start with the note D and add a note a major third above it (F# ) and a minor third above that (A) you end up with a D major chord. If you start with the note A and add a note a minor third above it (C) and a major third above that (E) you end up with an A minor chord.
If you go through and analyse all of the scale tone chords in the key of C major you end up with the following pattern:
This pattern remains the same regardless of the key. This means that if you look at the scale tone triads in any major key, Chord I is always major, chord II is always minor, chord III is always minor, etc. The only thing that changes from one key to the next is the letter names of the chords. This can be demonstrated by looking at the scale tone triads for the key of G major which are shown in the next example.
