The G5 chord on guitar is most commonly played as a power chord on the three lowest-pitched strings. On a six-string guitar with ordinary tuning, it is usually played on the third fret of the sixth string along with the fifth fret of the fourth and fifth strings. The first finger is placed on the sixth string. The fourth and third fingers press the fourth and fifth strings respectively.
The name of the G5 chord indicates that only octaves of the G note and its fifth note, D, are included in the chord. A less common variant of the G5, which has a slightly less powerful sound to it, uses open position for the third and fourth strings. Strings one, two and six are played at the third fret with fingers four, three and two respectively. The fifth string is muted by means of contact with the second finger.
The G5 chord works with G-major and G-minor keys as well as nearly any G scale making use of the fifth note. Fifth chords are nearly ubiquitous in contemporary popular music due in part to their simple-yet-flexible nature; they owe much of this rise in popularity to early rock and heavy-metal music styles.