'Whistler' is a biography of James Abbott McNeill Whistler, an American painter active during the American Gilded Age and based primarily in the United Kingdom. He eschewed sentimentality and moral allusion in painting and was a leading proponent of the credo “art for art's sake”. His signature for his paintings took the shape of a stylized butterfly possessing a long stinger for a tail. The symbol combined both aspects of his personality: his art is marked by a subtle delicacy, while his public persona was combative. He found a parallel between painting and music, and entitled many of his paintings “arrangements”, “harmonies”, and “nocturnes”, emphasizing the primacy of tonal harmony.