Caltrop

From holidaysforquince.com: Since the days of Black Sabbath, the promise of heavy rock music has been this: that a perfect series of riffs, reinforced by a tightly-wound rhythmic unit, can deliver very real psychedelic effects, forcibly altering one's conscious state of being. Though post-modern doomsters have toyed with elements of the formula (witness: Earth, Melvins, Isis, etc), the principle importance of the mono-riff has remained intact. World Class