Power chords are small chords with a big sound. The are usually played with an overdriven tone and often use the palm muting technique. They are basically small barre chords using fewer strings.

Power chords use the root note, the fifth and sometimes the octave. (The octave can easily be added as your little finger is already covering that note on the D string). This means that power chords are neither major or minor. They function as a way of giving single note riffs a bigger sound following the same pattern.

The basic power chord shape becomes even easier when using a drop D tuning where your bottom E string is lowered to a D. The same three notes can then be held with one finger.

Some bands tune all of their strings down so that the sound is lowered but the shapes remain the same. You can detune your guitar by various amounts and even use heavier gauge strings to help keep the tension from getting too loose.

Power chords are usually written as C5 (C and G), D5 (D and A) and so on.

Example 10a

These power chords sound particularly heavy because the lowest notes (on the E string) are actually not the root notes but the 5th an octave lower.

This make the chord progression E D E F D C# as the root notes are actually on the A string.

Example 10b