Ozzy Osbourne allegedly relived himself while recording a song on Blizzard of Ozz, according to engineer Max Norman on The Metal Voice. Ozzy Osbourne ‘List’ Of Zakk Wylde Replacements Leaked.
“Oh yeah, everything went by Ozzy. If Ozzy liked it, it was called, if he didn’t like it, then we’d fix it. He wasn’t just f**ked-up in a corner… well, not always.
“We do the vocals and it might take… Ozzy does one line at a time and then he doubles it. That’s why you had on the original album ‘Oi, oi, oi!’ There were only three of them, then when they did the remix, they somehow echoed it.
“But when he originally did it, we were working with just two tracks so he would do that, he’d go, ‘OK, roll it.’ He’d sing the first one and then he’d hold his hand up and I’d stop the tape, and you go, ‘How was it?’ And I go, ‘Yeah, not bad.’
“Ozzy said, ‘Do it again.’ So he punched the first line again and maybe after two or three takes, I said: ‘Yeah, pretty good that one.’ ‘Alright, double it.’ So I put him on the other track but he doubled the first line, ‘How was it?’ And I go, ‘Not bad.’ He goes, ‘Do it again.’
“And then you’d do it again, and you get that tight Ozzy sound of his vocal which he’s been doing for many, many years, that tight double. And that’s his sound even from Black Sabbath.
“So you get one, and then you hear the sound, you hear it phasing, flanging with itself, and you go, ‘Yeah, that’s a good one, go to the next line.’
“So to do the vocal, like this, it takes about six or seven hours to do the work, and in between, he’s having a slug of scotch or doing something else, mostly having a slug of scotch.
“And I remember I would punch in, and he wouldn’t be singing. And I’d solo it up real quick and crank it up, and I could hear this hissing sound, and he was actually just standing there taking a [pee] on the floor by the side of the mic.
“And then one of the times I punched in, he was throwing up. But most of the time he was very good, and actually, we did have the chance to listen to those moldy tracks many years later, and they are actually exemplary, they’re really good.
“His singing is really good, there’s no tuning on any of that stuff, that stuff is as it is.” Ultimate-Guitar transcribed his comments.