Backed by a screen full of psychedelic video streams and flanked by six flaming pyres, frontman Ozzy Osbourne, bassist Geezer Butler and guitarist Tony Iommi dressed all in black for the occasion.

(They were joined by drummer Tommy Clufetos, who has sat in for original drummer Bill Ward for several years.)

Iommi was pure thundering bliss on guitar. Playing some battered-up, well-used Gibson SGs, the legendary picker had a thick tone that was often menacing, sometimes forceful and always bursting with lightning.

Butler availed himself well, especially on the band’s more recognizable basslines such as “War Pigs.” And Culfetos beat the drums like he hated them.

Then there was the Ozzman.

Osbourne’s voice wasn’t great. It wasn’t awful, really. It simply wasn’t very good. On Wednesday, he was sometimes flat. He was sometimes pitchy, occasionally off-key. He almost never hit the notes he was looking for.

Osbourne did better on less vocally demanding songs such as “Dirty Women” and “Black Sabbath.”

It was the first show of the tour, so maybe his voice will warm up. Maybe they’re still working out the sound in his monitors. Maybe it’s just that he’s 67 years old.