He really is not only one of the most famous Canadians but one of the most famous classical performers of all time. Don't feel bad about not knowing who he is, but he is really famous.
Postjack, you should pick up those CDs if they dip in price again. I'm sure that in some point of your expedition of classical music you'll learn to love glenn gould's performances. Every single one I've personally heard is exceptional.
Edit: but it should be known that he does grunt and hum quite a bit.