My Dad liked the Porter Wagoner TV show, which I sometimes watched with him on late Saturday afternoons. The show was mainly about 1950s country music, which I retain a certain fondness for -- although I don't like country music from the 1960s on. Sometimes, though, Wagoner would bring on a bluegrass act. That's how I got familiar with the banjo, and familiarity with the banjo has come to mean familiarity with Earl Scruggs.
Much has been written about Scruggs this week, but none of it better than a tribute from Steve Martin, comedian and seriously good banjo player, in this article. Even if bluegrass is not your favorite, I think you'd agree that Scruggs redefined an instrument in the same way that Jean-Pierre Rampal did.
As for Doc Watson, I wasn't familiar with him until one night in Athens, Georgia, in the 1970s when my roommate dragged me along to a Watson concert. We arrived late, the place was full, and management gave me a barstool and pointed to the edge of the stage. Watson was six feet away. I was in awe and continue to be. He's now 89 and doesn't perform often, but I saw him in concert a few years ago. He still complains that his fellow musicians are out of tune by a hair... a micro-hair... a nano-hair. Such an ear is God's gift.