According to Carmine Appice, Metallica were the ones that started heavy metal

Appice recently shared his thoughts on who he believes actually invented heavy metal: Metallica, as said in an interview with W4CY Radio. 

Even Slayer. They weren’t that buzzsaw guitar back in the day. All those bands…they were hard rock. And then as the, per se, metal movement moved on and everybody started having that buzzsaw, Metallica kind of buzzsaw guitars and fast bass drums like Lars [Ulrich]. And I think that’s where it all started. All that stuff that’s going on today started with Metallica — in my eyes. I mean, I [could] be wrong. But for me, and all the stuff before that, including Black Sabbath, was hard rock. I mean, Black Sabbath was just, to me, like another Led Zeppelin coming out of Birmingham. I mean, we played gigs with Black Sabbath back in the day when they first came out with Cactus… We were rock blues and so was Black Sabbath. I mean, ‘Paranoid’, to me, back in the day was like a ‘Communication Breakdown’ [Led Zeppelin] kind of thing. And then as it went along and went along, I mean, their sound got thicker, but it still didn’t have that buzzsaw sound. That’s my own opinion. Everybody says Sabbath is heavy — they’re heavy hard rock.

Being a part of influential bands like Cactus and Vanilla Fudge, which helped to bridge the gap between blues-rock and what would later become heavy metal, makes Carmine Appice one of the most significant drummers in the proto-metal movement.