The guitarist was speaking to GibsonTV last month in a lengthy interview which covered his life and career in Black Sabbath, who bowed out for good in 2017.
Iommi recalled in the interview how Black Sabbath went about finding a new vocalist following the departure of the late Ronnie James Dio in November 1982.
“I phoned David Coverdale up, and he said, ‘Oh, I just got this band together, Whitesnake. Why didn’t you phone me before?'” Iommi said (46:00 in the below interview).
“I said: ‘Because [Dio] hadn’t left before; it’s happened now.'”
“It just went on a bit, and we couldn’t decide.”
Black Sabbath eventually hired Deep Purple frontman Ian Gillan, who recorded the 1983 album ‘Born Again’ before leaving the band.
Bolton’s apparent audition has become part of the band’s folklore, but the soft-rock singer dismissed it as just “a rumour” in a 2014 interview.
“That rumour about me auditioning for Black Sabbath was only a rumour,” Bolton told The Echo in 2014. “I don’t know how on Earth it started.”
In an interview last month, Ozzy Osbourne praised Iommi as “the greatest” guitarist but also admitted that his former Black Sabbath bandmate still “intimidates the fuck out of me — and he knows it”.