United Kingdom, May 2 -- Geezer Butler is having nightmares and "palpitations" ahead of Black Sabbath's reunion gig.

The band is getting back together to play one final show in their home town of Birmingham, England in July - and the bassist has admitted he's already worrying about the big day because there's so much pressure for them to give the crowd a good time.

He told the Guardian newspaper: "I'm already having palpitations. In fact, I had a nightmare last night.

"I dreamed everything went wrong on stage and we all turned to dust. It's important that we leave a great impression, since it's the final time that people will experience us live. So it has to be great on the night."

The 'Back To The Beginning' show at Villa Park on 5 J...