"When Tony Iommi deified himself in 1970 by unleashing upon the world that seminal riff from Black Sabbath’s infamous title track, he not only laid the groundwork for the future of heavy metal music, he also single-handedly executed one of the most noteworthy trills in rock ‘n’ roll history. Combined with the sound of pouring rain and the ominous ringing of the bell, his use of the trill on “Black Sabbath” demonstrated the latent power the classical embellishment has always held, but had hitherto never been actualized with proper amplification."