As Black Sabbath prepare for their farewell show this weekend, at least one member is choked up at the prospect of the band's final gig.

"My emotions are flying all over the place," Ozzy Osbourne told the BBC during rehearsals at Birmingham's Genting Arena, where the band will play its final show tomorrow night. "Since I've got to this building today, I've been happy, I've been tearful. Let's see what happens."

Black Sabbath kicked off their last tour, called the End, more than a year ago. After circling the globe, it wraps up this week with two shows in the English city in which they got their start in 1968. Saturday's performance will be their last, and Osbourne hinted that there may be a surprise or two for that final concert. "I've got to say something, but I've nothing rehearsed," he said. "I'm no good at speeches."

Osbourne told the BBC he was feeling sentimental about the end of the band's touring days, recalling an early gig in Birmingham and thinking, "This'll be good for a couple of years – drink a few beers and have a jam. But it was the beginning of the most incredible adventure you could think of. I've had the best life out of it. One of the proudest things I have in my heart is the fact that Black Sabbath wasn't a band that was created by some big mogul. It was four guys who said let's have a dream, and it came true beyond our wildest expectations."

In 2013, three of the four original band members – singer Osbourne, bassist Geezer Butler and guitarist Tony Iommi – reunited for the 13 album. Drummer Bill Ward, who's had issues with Osbourne, wasn't invited to participate in the record or on the tours that have kept Sabbath on the road for much the past few years.

And unlike other artists – including Osbourne himself – who've announced farewell tours in the past, only to return later, the singer insisted that Black Sabbath's show Saturday night will be their final one. "This is definitely it," Osbourne said. "It's run its course."

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