Original sentence: "Power chords" consist of perfect fifths and fourths and may be considered triads which lack the third and thus double the root or fifth to create a third note.Popularized by heavy metal music they are used extensively in many kinds of rock music, especially (see below)
Edited sentence: "Power chords" are based on triads but always lack the third; the root and possibly the fifth are simply doubled in octaves.They are used extensively in many kinds of rock music (see below)