I saw Leo play in Ann Arbor in 1977, I believe. I shall never forget the feeling that concert gave me. Certain virtuosos tell you things about the instrument they play that make you glad to be a human being. Vladimir Horowitz had the same effect on me when I heard him around the same time.
Leo Kottke is amazing. He just seems to conjour up feeling with his playing or his voice, and that is indeed a rare quality among musicians to really be able to communicate both worlds to the listener.