Udo Dirkschneider is the rasping tank-commander who made Accept's choruses feel like steel boots on concrete. I heard him first with Accept (1976-1987), and by the early '80s he was turning "Fast as a Shark" into a riot alarm, then stomping out "Balls to the Wall" and "Metal Heart" with that clipped, unforgiving bark. He quit in 1987, built U.D.O. (1987-1992; 1996-present) to keep the machine running when the business wanted prettier noises, returned for Accept stints (1992-1997; 2005), and later toured as DIRKSCHNEIDER (2015-2016) to give the classics a proper bruising. He doesn't sing at you; he drills through you, like a shout trapped inside a turbine. That voice is half attitude, half armor.