When I was a twenty-year-old aspiring musician, I met a man in his retirement named Jon who would become my musical mentor, and even more importantly, my friend. — He lived in Paris and I lived in North Carolina (then Ohio, then Texas, then Germany, then Texas, then Louisiana, then Texas, then…Norway!!). So, by necessity, we became email penpals. Jon was and is an exceptional teacher. I never apprenticed with him formally, but I visited him several times in…