Watch the Diads & Power Chords online guitar lesson by Robbie Calvo from Guitar Interactives
PRINCIPLE 2 - DIADS (2 note chords) / Power Chords
A diad (di, meaning 2) is a 2 note chord that consists of a root and a perfect fifth.
Diad chords are built by taking the root note and the note a fifth above it. For example the chord G5 is built by using the notes G - A - B - C - D - E - F# - G. The resulting chord is a G5 chord. 5 chords or power chords as they are known are neither major or minor in quality and can be played over either to add punch and power.
Let’s build the second diad in the key of G:
G - A - B - C - D - E - F# - G. The resulting chord is an A5 chord.
As we build the 7 diads through the scale of G we’ll see that the first 6 diads all have a root and a perfect 5th above them. These chords are consonant and are commonly used as power chords in rock music because of their uncomplex sound and sonic stability when played using overdrive or distortion. The other reason they are used so much in rock music is that we can use 6 of them in one key regardless of whether the chords in musical progressions are major or minor in quality. This will become clearer as we progress through the 5 harmonizing phases.
The 7th diad consists of a root and a b5th interval. This interval is also called a diminished interval. The diminished fifth diad can also be used in rock music but has a dissonant sound that will be tense and need resolution. It does not have the same sonic stability and strength as the other 6 diads with perfect 5th intervals.
You can practice your 7 power chords over the tracks I’ve provided.