Power Chords
A power chord is just two notes: the root and the perfect 5th. With no 3rd, it is neither major nor minor — just raw, strong, and clean even under heavy distortion. Power chords are the backbone of rock, punk, and metal.
Why Only Two Notes?
A power chord's formula is simply [0, 7] — root and perfect 5th. The strength lies in what it omits: the 3rd. Without a major or minor 3rd, the chord is harmonically neutral. This ambiguity, combined with the perfect 5th's consonance, creates a sound that is strong and clean even under heavy distortion.
When a guitar amp distorts a major or minor chord, the complex overtones of the 3rd create muddy, dissonant artifacts. Power chords avoid this because the perfect 5th's simple 3:2 frequency ratio produces clean overtones even at extreme gain. This is why power chords dominate distorted electric guitar music — from Black Sabbath to Green Day to Metallica.
Playing Power Chords
Power chords are typically played on the lowest 2-3 strings, often doubling the root an octave higher (making the pattern [0, 7, 12]). On guitar, the shape is simple: index finger on the root, ring finger two frets higher on the next string. This shape is moveable to any fret, making every root accessible.
The flat-5 power chord [0, 6] replaces the perfect 5th with a tritone. It is dissonant and aggressive — the opening of "Black Sabbath" by Black Sabbath uses this sinister interval.
In ChordColor
A power chord shows just Red (root) and Blue (perfect 5th) — the simplest visual pattern of any chord type. The flat-5 power chord shows Red and Teal (tritone).