Relevance, regardless of your profession, depends heavily upon the expertise you command. For a musician, if you have a broad knowledge of music, are comfortable playing in a wide variety of styles and know something about music history and theory, you’ll have the breadth. Now comes the depth part. You must have expertise and high proficiency in the areas of your concentration. You have to be competitive with others who are doing the same kind of work that you do. In down-to-earth terms, you have to be unbelievably good at what you do. Importantly, as your career develops and the years pass, it’s critical that you keep expanding in both your musical breadth and depth. Be a life-long student, and the chances of keeping your edge—ergo, your relevance—increase tenfold.