One of the true staples of the sound of hard rock and metal is the use of repeated pedal tone figures to drive heavy riffs and rhythm parts. A pedal tone is a sustained tone, typically in the bass, that is performed while at least one additional harmony is sounded in another register.
Within the scope of rock and metal guitar playing, this often translates to the repeated striking of a low note on the sixth or fifth string (typically open) that alternates with higher single notes or chords. Two classic examples of pedal tones used this way are Judas Priest’s “Another Thing Comin’ ” and the verse figure to the Ozzy Osbourne classic “Crazy Train.”
