For Scott Ian, having the chance to work with Roger Daltrey was a dream come true -- until he was asked to critique the long-time Who frontman's performance.

Anthrax was putting the finishing touches on 'Taking the Music Back,' a 2003 single from 'We've Come for You All,' when Ian mentioned to his wife Pearl Aday what a perfect fit it would be for Daltrey's leather-lunged style.

Aday, as Ian relays in his forthcoming memoir 'I'm the Man: The Story of That Guy from Anthax,' knew how to get in touch. After all, she's the adopted daughter of rock royalty in Meat Loaf; her biological father was the drummer in Janis Joplin's Full Tilt Boogie band.

"So, she arranged a dinner for the four of us," Ian writes in 'I'm the Man,' due Oct. 14 via Da Capo Press. "There I was with the lead singer of the band whose guitarist inspired me to pick up my first guitar, drinking bottles of wine and laughing. We were there for about four hours, and Roger told us amazing stories about the Who. Then we started talking about Anthrax, and he volunteers to do guest vocals. I didn't even have to ask him."

Back in the studio, Ian says it took a moment for Daltrey to get his bearings amid Anthrax's decidedly muscular groove. "He said, 'This is heavy, heavy stuff,' over and over," Ian adds. "I was like, 'Man, this is like a pop song for us.' ... But he kept listening, and after about 40 minutes, he was able to separate the parts and come up with a vocal for the chorus. [Anthrax singer] John [Bush] did most of the vocals, but for the chorus Roger came in with that trademark scream and just killed it."

Once they'd nailed down a take, however, Daltrey turned to Ian to find out how he'd done.

"That was completely surreal," Ian says, "sitting there critiquing the vocals of one of the greatest singers in rock. I felt like I was in Pete Townshend's chair, thinking, 'How the f-- did I get here?' So, of course, I answered Roger with, 'Yeah, that was alright, but why don't you do it again with a little more energy?' Not!"

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