James Abbott McNeill Whistler was an American artist active during the American Gilded Age and based primarily in the United Kingdom. He was averse to sentimentality and moral allusion in painting, and a leading proponent of the credo "art for art's sake". He found a parallel between painting and music and entitled many of his paintings "arrangements", "harmonies", and "nocturnes", emphasizing the primacy of tonal harmony. His most famous painting "Arrangement in Grey and Black No. 1" (1871), commonly known as "Whistler's Mother", is a revered and often parodied portrait of motherhood and another Whistler exercise in tonal harmony and composition.