When Ozzy Osbourne was unceremoniously fired from the pioneering Black Sabbath in the late '70s for his reckless, drug- and alcohol-fuelled antics, you may as well have put guns to the heads of Tony Iommi, Bill Ward and Geezer Butler and pulled the triggers for all the hope that they had moving forward.
How on Earth could Sabbath carry on with Ozzy? It would be like the Beatles without Lennon/McCartney, or Led Zeppelin without Robert Plant!
However, who stepped up to the plate and turned the impossible into the very possible? Only the immortal Ronnie James Dio, of course. At the time famous for his work with Elf and Ritchie Blackmore's Rainbow, Dio single-handedly gave Sabbath a much-needed shot in the arm for Heaven & Hell (1980).
The album not only redefined Black Sabbath as the doom metal juggernauts fans already knew and loved thanks to its crushing title track, but it also gave the band the opportunity to up their speed and melodies in order to keep up with the then-burgeoning New Wave of British Heavy Metal, which was being spearheaded by equally harmonic and grandiose groups like Def Leppard and Iron Maiden.
For achieving the impossible and (in the mind of this humble writer) crafting the best Black Sabbath album of all time, Ronnie James Dio's work and influence on Heaven & Hell puts the man and the record right at the top of this list.