One of the things I’ve learned as a string teacher is that good habits can often replace a student’s bad habits quickly, because the good habits make playing easier. But it was Mark Twain, strangely enough, who helped me to realize that the switch can only result from a very conscious and rational process on the student’s part, a process of understanding and acceptance. In his essay “Taming the Bicycle,” Twain wrote, “In order to keep my position, a good many things were required of me, and in