Charles Henry Caffin was an art critic and author, and the editor of the Studio in America.
He suggested that Harmony in Green and Rose: The Music Room y034 was influenced by Japanese woodblock prints, particularly those of Kitagawa Utamaro (ca 1753-1806).
Caffin, Charles Henry, 'James McNeill Whistler', The International Studio, vol. 20, no. 79, September 1903. Caffin, Charles H., American Masters of Painting, Garden City, 1913