In the 1980s, an American thrash metal juggernaut named Metallica dominated the landscape of heavy music, with their breakthrough record in 1991 serving as the cherry on top. The heavy metal torch was eventually passed to Pantera in the 1990s, and then to Slipknot throughout the 2000s. These transition periods within the genre have continued, but all of these lengthy tree branches have led straight back to the Prince of Darkness. CFRA Live technical producer Stephen Ellsworth explains how Black Sabbath frontman Ozzy Osbourne directly and indirectly shaped the world of heavy metal as we know it.