power chord

Pete Townshend of The Who is an avid user of power chords and is credited with coining the name.

A power chord, also known as 5 chord or 5th (for example, an E power chord is denoted E5 or E 5th), is a chord that, in its simplest form, consists of just a root note and the perfect fifth above it. (By some definitions, this makes the power chord not really a chord at all but merely an interval.) Because the third is absent, a power chord is neither major nor minor and, because of that, can take the place of a normal triad major or minor chord.

E major: E, B, E, G#, B, E

E5 (E power chord): E, B, E, B, B, E

E5 added 2nd: E, B, F#, B, B, E

Power chords are commonly heard in rock music, especially hard rock and heavy metal, on electric guitars played with distortion. One of the features of distortion is that it transforms the audio signal in a non-linear way, generating additional harmonics at the sums and differences of any notes being played. If chords containing three notes or more are put through distortion the result can be an unpleasant mix of dissonances. However, because the ratio between the frequencies of the root and fifth is very close to 3:2, when a power chord is played through distortion, harmonics closely related in frequency to the original two notes are produced, giving a more distinct and coherent sound. Also, the spectrum of the sound is expanded toward both higher and lower frequencies, resulting in a richer, more powerful sound than the undistorted notes alone.

Power chords are often played with octave doublings of the root and/or the fifth. An example of this on the guitar is the six-note E5 power chord (shown in the second diagram of the block above), consisting of EBEBBE, spanning two octaves and played using all the strings. Inversions of power chords are also possible in which the bass note is the perfect fourth below the root.

Variations on the power chord

Just playing 5th chords can end up sounding samey. Additional tone colors can add interest and variation without detracting from the basic tonality. For example, the 5th chord can be played with an added 2nd interval, as shown in the third of the fretboard diagrams above.

Other chords that don't incorporate the major or minor 3rd are also often used in conjunction with power chords. Because of the simplicity of the two- or three-note structure of power chords, many players have used them combined with melody figures.

Power chords in various keys

As well as E, G, A, C, and D power chords can all be played in open position on the guitar as shown in the charts below. They are displayed next to the major chords from which they are derived, and also the variations obtained by adding a 2nd. In these diagrams, and 'X' means that the string should be damped or not played.

G major: G, B, D, G, B, G

G5: G, mute, D, G, D, G

G5 added 2nd: G, A, D, G, D, G

A major: mute, A, E, A, C sharp, E

A5: mute, A, E, A, E, A

A5 added 2nd: mute, A, E, A, B, E

C major: mute, C, E, G, C, E

C5: mute, C, mute, G, C, G

C5 added 2nd: mute, C, mute, G, D, G

D major: mute, mute, D, A, D, F#

D5: mute, mute, D, A, D, A

D5 added 2nd: mute, mute, D, A, D, E

Movable power chords

Power chords are popular not only because they're effective in certain kinds of music but also because many of the two- and three-note forms are easy to play, enabling fast chord changes. The same rules that apply to the E chords described above apply to the movable chords based on the barre F and B flat chords shown below. Playing the bottom two or three notes of each of these chords gives the 5th chords. As these movable barre chords can be played all the way up the fretboard, a large number of power chords can be devised for virtually all keys.