 He also wrote several non-fiction books about music including "Schumann" (1906), "The Religion of Music" (1909), "The History of European Music from 1850-1914" (1914) and "The Heroes of the Orchestra" (1921) which contributed greatly to French awareness of musical trends in turn-of-the-century Paris.As art critic at the "Mercure de France", he attacked artists such as Paul Gauguin and Henri de Toulouse-Lautrec, though he expressed his admiration when their work became accepted.Later in life he wrote mainly nonfiction, including travel writing such as "Normandy" (1939), biographies of writers, artists, and musicians, and art criticism.