Crash Course in Chord Theory for Guitarists
2 Power Chords and Suspended Chords
So, a major chord is note 1,3 and 5 of the major scale. A minor chord is notes 1,3 and 5 of the minor scale. A “Power Chord” is made of only 2 different notes, the 1st (root) and the 5th.
Here are the major and minor scales in the key of C.
C major scale = C D E F G A B C
Root 3rd 5th
C minor scale = C D Eb F G Ab Bb C
Notice that the root note (C) and the 5th (G) are the same in both major and minor scales.
A "power chord " is made by playing these two notes together.
C major: Root, 3rd & 5th C minor: Root, 3rd & 5th C5 (Power Chord)
of C major scale of C minor scale Root & 5th only
The power chord omits the musical information to tell us whether the chord is major or minor (the 3rd note of major or minor scale). This means we can use it in place of either one of them, but with the loss of that information. However there's a particular sound to a power chord and it's often the chord of choice because of this.
Here’s one fingering for the C power chord (C5) on a piano.
Back on guitar, up the fretboard, by getting rid of the open string and adding an extra instance of the root note, we get the more familiar, beefier sounding, and moveable power chord shapes shown below .
3) Suspended Chords
A suspended (sus) chord is a twist of the major chord.
There are two types, a Sus2 (Suspended 2nd) and a Sus4 (Suspended 4th)
C major scale: C D E F G A B C
C major = 1st 3rd and 5th notes = C E G
Csus2 = 1st, 2nd and 5th notes = C D G
Csus4 = 1st 4th and 5th notes = C F G
By using the 2nd or 4th note in place of the 3rd we "suspend" the chord away from its usual sound, and it adds a little tension to things. You can always experiment with using the corresponding suspended chord anywhere a major chord is indicated to add interest to things.
Let’s now look at this same idea in relation to a D major chord.
Here’s the D major scale: D E F# G A B C# D
Try it on the piano
We now have to use the black keys to make the major scale. The F# and C# are black notes to the right of the F and C white notes correspondingly. The 8 note sequence should still sound like “do re me fa so la ti do”.
When it does, you can play the notes of these chords to hear the difference.
D major = 1st 3rd and 5th notes = D F# A
Dsus2 = 1st, 2nd and 5th notes = D E A
Dsus4 = 1st ,4th and 5th notes = D G A
On a guitar, the sus chords are easily made from a plain D major,
by changing the note on the top string.
Click on each of the chord boxes above to hear them. The sus chords are followed by a plain D major, so you can hear the tension being resolved as the suspended note (E or G) moves to the major 3rd (F#).
Click below to hear a few examples of the Dsus chords in use. You may recognise a few of them.
D E G A B D