When Ronnie James Dio joined metal legends Black Sabbath in 1980 the former Rainbow frontman’s appointment couldn’t have come at a better time. Sabbath were a sinking ship. A drowning vessel from which enigmatic frontman Ozzy Osbourne had been trying to escape for some time. However, even though it was painfully clear that new blood had to be added to halt the band’s alarming deterioration the hostility that greeted Dio from some corners was quite shocking.