Peabody, The author is writing primarily from a jazz context (he is a piano player). Of course the idea is to get better at all of these things. The point is that by practicing in a variety of different ways, not only are you pushing the limits, you are becoming infinitely familiar with what is in front of you. By learning something so completely that it is effortless, requiring no conscious thought, then true mastery can be attained. Itâ€™s not a concept that I can do complete justice to in this response. If you havenâ€™t read Wernerâ€™s book, find a copy. Youâ€™ll be glad that you did!