• Understand how root-fifth shapes can alter basic harmony.
• Create more interesting guitar parts by layering different sounds.
• Learn how to imply more complex tonalities with standard power chords.
Chords that contain only a root and 5, which everyone knows by the moniker “power chords,” are an essential part of the arsenal of every modern guitarist, especially in rock, pop, metal, and even country. A power chord is just a triad without the 3. Lacking a 3 or b3, power chords are neither major nor minor, and it’s this absence that lends the chord its utility because the ambiguous power chord can stand in for the triad built on almost any root within a key or outside of it. Unfortunately, this same characteristic can make compositions made up only of power chords sound stale and less than complete.
But with a little music theory exploration (and a guitar buddy), power-chord rhythms can take on a very hip, multidimensional character. You just need to add a second guitar part. It’s easier than you might think, and keeping it simple is the key. In each of these six exercises, you’ll master a familiar root progression and easy secondary riff, which unite to form rich, complex tensions. The progression will employ a combination of open-position root-fifth grips and the familiar, three-finger power-chord shapes. We’ll also probe the theory that makes each progression work. So grab your axe, fire up the tubes, and let’s jam.
Fig. 1 is a repeated Im–III–VI–IVm progression, finished off by a VII–III–Im in E minor (when the rhythm guitar comes in, follow the root progression indications between the staves).
In the right channel is a simple riff consisting only of the notes G and B in the 12th position— scale degrees 3 and 5 of the key. On the Im chord, E5 combines with G and B in the riff to form a full Em triad voicing. Next, the G5 is transformed to a G triad due to the B, and then it gets a little tense. The addition of B to the C5 chord gives a very bright Cmaj7 voicing. In a similar way, B and G create major 9 (B) and minor 7 (G) sounds over the A5 chord.
In a nifty turn at the end, G and B suggest a full dominant 13 chord when played over D5. And finally, while the rhythm guitar plays what is actually a V chord (B/D#), the G in the riff changes the character of that chord completely, morphing it into a G augmented triad, before heading back to Em.