I think that I might have seen Winifred Atwell on the telly once, Canary42, but, other than that, she was unknown to me in my childhood.
I'd never heard of Elvis Presley, Bob, until (at the age of 8) my family went to visit my aunt, uncle and cousins in Essex. Their kitchen wall was covered in pictures of a man I didn't recognise. When I asked who he was, my cousins were amazed that I'd never heard of Elvis!
Of course I hadn't though, because (apart from hearing Russ Conway, Perry Como, Doris Day, et al on 'Housewives Choice' with my mother during the school holidays), 'music' in our house strictly meant Mozart, Tchaikovsky and Beethoven and, for a little light relief now and then, Gilbert and Sullivan. I was only allowed to listen to Children's Favourites, on the Light Programme on a Saturday morning, on the STRICTEST of conditions that I turned the radio off IMMEDIATELY afterwards. If my mother heard even the tiniest snippet of Brian Matthew's voice at the start of Saturday Club, I'd be in trouble for the whole of the following week!