Power Chords or Fifth Chords
The chords are made up of 3 notes, in this case the Power Chords only include 2, what really more than a chord is an interval:
Root - Perfect Fifth (R - 5)
You can also repeat the Root (R – 5 – R)
They are represented only with the letter that represents the name of the chord followed by the number "5" that represents the interval of R - 5, for example Do Power Chord is represented as C5.
* In the examples we will use the 2-note version, with the repeated root represented as imaginary.
They are generally used in Genres such as Rock, Blues Y Metal. It is common to use them on guitars with distortion, and making use of the technique Palm mute.