Geezer Butler says he and his Black Sabbath bandmates felt a sense of shock when they watched Kiss for the first time.

It was 1975 and Gene Simmons and company were out opening for Sabbath on their U.S. tour. During a recent conversation with Rock Cellar, Butler admitted his band was taken aback by the theatrics of their opener.

“Kiss was the first band that ever used stage production,” the bassist explained. “Up until Kiss came, bands like Black Sabbath used to just go on and plug in and play. Kiss was the first one to use pyro. You’ve never seen that. I mean, the shock of that. And they were supporting us, so they weren’t even headlining.