Metal Hammer magazine recently compiled a list of 50 iconic metal riffs, and asked a group of top guitarists in the genre to list their favorite. Once the votes were tabulated, Black Sabbath's "Symptom of the Universe"—a cut from their 1975 album, Sabotage—came out on top.
"Symptom of the Universe" is frequently cited in particular as a hugely influential track in the development of thrash metal as its own sub-genre.
When asked about the omission of the song—and one or two other classics—from the setlist of Black Sabbath's final concert in Birmingham, England on February 4, 2017, guitarist Tony Iommi told Guitar World; "We could only do songs that Ozzy could still sing. That’s no disrespect to him. When we recorded those songs originally 30 years ago, the keys were so high there was no chance in hell that he could still hit those notes. But it would’ve been nice to have had them in the set."