While these sayings are fun, and sort of true, they are kind of not useful. You should be a jack of various trades, a master of some. Specialization is for insects :)
Having achieved expertise/mastery at a couple of different things (software deployment, guitar playing, other things), I find all sorts of common patterns between these seemingly unrelated skills, patterns I can then reapply for other skills. For example, being an improvisational musician has made me keenly aware of the passage of time, and immutable deadlines - an awareness that helps me with every other skill that involves the passage of time.
I also like what you said about your knowledge of music was useful to your programming skills. Being well-rounded individuals can make us better specialists.