A musical chord which is not technically a chord since it only contains two pitch classes (making it an interval). It is formed by the root note, 5th and commonly features the octave above the root.
It is used by rock guitarists way too often by stringing different power chords together to form a riff
. This goes against western diatonic music theory which says you should not have parallel 5ths or octaves, let alone both of them simultaneously. Despite this fallacy, rock guitarists have chicks
and money while classical musicians have neither. Go figure.