power chord

A power chord is the root and the fifth of a chord, 7 semitones apart, and no third. That is why one shape works where a major chord would sit and where a minor chord would sit. A fifth measured in the opening bar of Bach's C major prelude comes out at 706.21 cents.

Built — the root, the fifth 7 semitones above it, and usually the root again an octave above that.
Written — the root's letter name and a 5, as in E5. The 5 names the interval, not a number of notes or strings.
Missing — the third. 4 semitones above the root would make it major, 3 semitones would make it minor.

What a power chord is

A power chord takes the root and the note 7 semitones above it, the perfect fifth, and stops there. E5 is E and B: B is 7 semitones above E. The usual three-string version adds the root again an octave up, twelve semitones above the root, so the last gap, from the fifth to the octave, is 5 semitones.

Two shapes, one for each root string

Every shape on this page was built by the site's power-chord module from the root and the string you start on, then checked note by note: every sounding pitch is the root or its fifth, and both are present. One fret is one semitone, so the same block moved up the neck is the same chord a semitone higher.

A5, frets 5 7 7 x x x

A5, root on the sixth string

A5 frets from the sixth string to the first: 5 7 7 x x x.

A5 spelling: A, E.

A5 sounding notes: A2 (1), E3 (5), A3 (1).

A5 open strings: none.

A2 up to E3 is 7 semitones, and E3 up to A3 is 5 semitones.

D5, frets x 5 7 7 x x

D5, root on the fifth string

D5 frets from the sixth string to the first: x 5 7 7 x x.

D5 spelling: D, A.

D5 sounding notes: D3 (1), A3 (5), D4 (1).

D5 open strings: none.

D3 up to A3 is 7 semitones, and A3 up to D4 is 5 semitones.

× mute · ○ open · green root · terracotta other chord tones
Numbers show a suggested finger: 1 index · 2 middle · 3 ring · 4 pinky. A bar means one finger holds several strings. Frets run from the sixth string, low E, to the first string, high E.

Why it is neither major nor minor

A major triad puts its third 4 semitones above the root and a minor triad puts its third 3 semitones above it. A power chord has no third at all, which is why it is neither major nor minor, and why a player can use it where either one would sit. The fifth is 7 semitones above the root in both of those triads and in the power chord, so it is the one note they share besides the root.

C major, C minor and C5, with the semitones between the notes
Chord	Notes	Semitones above the root	Gaps
C	C, E, G	0, 4, 7	4, 3
Cm	C, Eb, G	0, 3, 7	3, 4
C5	C, G	0, 7	7

A measured fifth

C4 is 262.86 Hz and G4 is 395.26 Hz. 395.26 ÷ 262.86 = 1.50369, and 1200 × log2(1.50369) = 706.21 cents for the fifth itself. Equal temperament puts seven semitones at 2^(7 ÷ 12) = 1.49831, which is 700.00 cents, so this fifth is 6.21 cents wider than equal temperament. A just 3:2 fifth is 1.50000, or 701.955 cents, and this one is 4.25 cents wider than that. C4 (MIDI 60) is 440 × 2^((60 − 69) ÷ 12) = 261.63 Hz, and G4 (MIDI 67) is 440 × 2^((67 − 69) ÷ 12) = 392.00 Hz. The two peaks are 132.40 Hz apart, and C3 is 130.81 Hz.

The bar is bar 1 of Prelude No. 1 in C major, BWV 846, played by Kimiko Ishizaka and released under CC0 1.0. Johann Sebastian Bach died in 1750, and Book I of the Well-Tempered Clavier is dated 1722. The 1893 G. Schirmer edition prints the opening bar as a C major chord, and C and G are both among the pitch classes the analyser finds there. The bar runs from 1.42 to 5.71 seconds of the recording, the analysis window lies inside it at 1.77 to 2.97 seconds, and the script picks that window by energy rather than by the interval it gives. The strongest pitch classes in that window were G, E, C. Hear on this page uses the site's sampled guitar, not that recording.

The recording's credit and licence are on sound credits.

Where players reach for it

An octave is a 2:1 ratio and a fifth is close to 3:2, the simplest ratio after the octave. Distortion adds frequencies that are not in the chord. Wikipedia's entry on power chords describes the effect as intermodulation distortion and notes that the root and fifth ratios stay close to the just interval 3:2. The measured ratio on this page is 1.50369. The shape also moves in parallel: players slide the same two or three strings instead of changing fingering, and one fret is one semitone.

Common misreadings

Is a power chord major or minor?

Neither. The third is missing: 4 semitones above the root would make it major, 3 semitones would make it minor, and a power chord has neither.

Does the 5 mean five notes?

No. E5 is E and B, two notes, or three when the octave is added. The 5 names the fifth, 7 semitones above the root.

Is a power chord played on the fifth string?

Not necessarily. The two examples above put the root on the sixth string and on the fifth string, and both add the octave on the next string down. The 5 in the name has nothing to do with which string you start on.

Why are power chords used with distortion?

What is the cents number on this page?

Where the other power chord pages fit

Power chord guitar chart is the reference: every root on both root strings, two or three notes, with export and print. How to play a power chord is the practice page: one chord, G5, played slowly. This page is the idea: what the 5 names, what is missing, and one measured fifth.