In Italy in 1916, Busoni met again with the artist Boccioni, who painted his portrait; Busoni was deeply affected when a few months later Boccioni was killed (in a riding accident) whilst on military training, and published an article strongly critical of war. An expanded re-issue of Busoni's 1907 work "A New Esthetic of Music" let to a virulent counter-attack from the German composer Hans Pfitzner and an extended war of words. Busoni continued to experiment with microtones: in America he had obtained some harmonium reeds tuned in third-tones, and he claimed that he "had worked out the theory of a system of thirds of tones in two rows, each separated from each other by a semitone".