Trill (music)

"Historically, the trill has acquired associations with doom, gloom, and even the occult. More specifically, two noteworthy composers, Guiseppe Tartini and Franz Schubert, adopted the trill to express a sense of melancholy in some of the most definitive pieces of their oeuvre. While these composers were certainly not the only ones to use the trill in incisive ways, their use of the classic embellishment distinguished their work."

"The trill [is] a technique that early composers used due to its rhythmic, melodic, and harmonic properties. By rapidly alternating between two adjacent notes—usually a half-step or whole-step apart—composers could create a brief sense of dissonance and tension that clashed with the tonality of the respective piece. The trill naturally creates a sense of tension, and when used properly, it lends itself well to somber moods and melodies. Metal musicians picked up on this early on and, by passing it down through the airwaves, have made it a hallmark of heavy music today."

"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."