I moved to the US a month shy of my 14th birthday. On my first day of school, I noticed that a whole bunch of kids were wearing t-shirts that said "DIO" on them (a few others had Y&T t-shirts). It turns out there had been a concert the night before, and I found out in short order that Dio was a band. A few months later, I bought the cassette tape that would shape my music direction forever" K-Tel's compilation Masters Of Metal! Besides Rush and Maiden, it had a Dio tune; it was either Rainbow In The Dark or Holy Diver (there was a second Masters Of Metal tape!), but that's a story for a different day!
A short time later I got both Holy Diver and Last In Line and those albums have regularly been in my playlist pretty much ever since. I saw Dio in concert a short while later, dragon slaying antics and all. I also saw him in 2000, 2004 and 2009.
As far as his musical output, I'm basically a pretty big fan of his stuff from Rainbow on, but his recording career goes way back to 1959! His first recordings were doo-wop tunes, and even at that stage you could totally tell it was him! I think Dio's long, constant recording/performing artist career is unparalleled in Rock. In addition, he was part of three legendary, must-have albums: Rainbow's Rainbow Rising, Sabbath's Heaven And Hell, and his own Holy Diver. I hope his wife, Wendy, goes to the archives and release it all!
I never met him, but he seemed to be a pretty decent guy, a good businessman and very appreciative of his fans. His philosophy in life seemed to be basically "be a good person", and it certainly came out in many of his songs when he wasn't singing about dragons and rainbows and Magica!
So the Rock world lost a true giant and legend. I'll close with a few lines of his Rainbow song A Light In The Black:
Something's calling me back,
There's a light in the black,
am I ready to go?
I'm coming home.
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The image above is credited to SHF's RTurner who worked the projection booth for Ronnie's memorial service in L.A.