Editing Rhythm guitar (section)

===Rock and pop harmony===
{{See also|Chord progression}}
Harmonically, in rock music, the most common way to construct chord progressions is to play major and minor "[[Triad (music)|triads]]", each comprising a root, third and fifth note of a given [[scale (music)|scale]]. An example of a major triad is C major, which contains the notes C, E and G. An example of a minor triad is the A minor chord, which includes the notes A, C and E. Interspersed are some four-note chords, which include the root, third and fifth, as well as a sixth, seventh or ninth note of the scale. The most common chord with four different notes is the [[dominant seventh]] chord, which include a root, a major third above the root, a perfect fifth above the root and a flattened seventh. In the key of C major, the dominant seventh chord is a G7, which consists of the notes G, B, D and F.

[[Three-chord progression]]s are common in earlier pop and rock, using various combinations of the '''I''', '''IV''' and '''V''' chords, with the [[twelve-bar blues]] particularly common. A four chord progression popular in the 1950s is I-vi-ii-V, which in the key of C major is the chords C major, a minor, d minor and G7. [[Minor chord progression|Minor]] and [[modal chord progression]]s such as I-bVII-bVI (in the key of E, the chords E major, D major, C major) feature in popular music. 
[[File:Power-chord-e.png|thumb|right|200px|A power chord in E for guitar. This contains the notes E, B (a fifth above) and an E an octave higher.]]
In [[heavy metal music]], rhythm guitarists often play [[power chord]]s, which feature a root note and a fifth above, or with an octave doubling the root, all without the third of the chord. Power chords are usually played with [[distortion (music)|distortion]].