The making of music is not the only valuable work that is done partly or sometimes for money and partly or sometimes "for nothing" (that is, for other reasons). One might mention cooking, child care, teaching, sexual intercourse, and computer programming. Such coexistence leads to various conflicts within & between persons, as we have seen.

A well-known poem on that subject is "Two Tramps in Mud Time" by Robert Frost. He is sometimes embarrassingly smug (I could do without his "life of self-control", and surely, in all charity, "yield who will" ought to be "yield who must"), but he does lay out one issue.

In case you want to read a view from the opposite extreme to the one that started this thread, here is my review of Elijah Wald's book.