Metallica's Kirk Hammett named one particular guitar riff that he believes "shifted heavy metal." "The first three Black Sabbath albums are like gospel. Everyone kind of universally agrees.

He took one of the basses to a Metallica rehearsal when they were working on their guitar rigs ... But the real challenge for ...

And of course, Hammett says Black Sabbath’s first three albums “are like gospel” to metalheads. Specifically, the Exodus co-founder lists the 1975 song “Symptom of the Universe” as one that changed ...