Power chords--formed by the root note and fifth note of a given key--are an essential part of the sound of rock, punk and other genres of music. Although they are typically played on the guitar, bassists can use power chords as well--adding a deeper punch to the band's overall chord sound. The good news about power chords is that if you know the notes on the top two strings (E and A strings on a four-string bass) then you can quickly and easily play power chords by adding one additional note (the fifth) with the root notes you play with your index finger.
Forming the Power Chord
Locate the G note on the E string (third fret) and press it down with your index finger.
Locate the D note on the A string (fifth fret) and press it down with your ring finger.
Strum these top two strings together to play the G power chord.
Move your index and ring finger down one string each to form a C power chord.
Move your index finger up to the fifth fret and your ring finger up to the seventh fret to form a D power chord.
The name of the power chord is determined by the root note that is played by your index finger. If your index finger is on G when holding a power chord then the chord is a G.
Notice that the power chord shape is easily movable up and down the neck; you can quickly change chords by moving your two fingers as a unit around the neck.