Walter Marchetti (1931 Canosa di Puglia, Italy – 2015 Milan, Italy) was an Italian avant-garde musician and composer. Departing from serial music, passing through the aleatoric musical precepts of David Tudor and John Cage, he is considered a pioneer of concrete music. He initially took courses with Bruno Maderna in Milan, later participating in the Internationale Ferienkurse für Neue Musik in Darmstadt. While in Milan, he met Juan Hidalgo. The two would later move to Madrid, where they founded the Zaj Group in 1964. Distinguished by its minimalism, the composition booklet Arpocrate seduto sul loto (1968) became the central reference for the series of editions published by Edizioni Conz in 1983. Informed also by participatory events of Fluxus, Marchetti’s performances are characterized by airy erratic tunes and visual dynamic elements. Regarded by Robert Ashley as one of the most beautiful piano pieces ever made, Natura Morta (1979–80) is a composition presented for a grand piano covered with fruit and vegetables and is notable for its quiet but steady tones. Returning to Milan in 1973 after Zaj’s extensive American tour, in the following years Marchetti performed in important Italian theatres such as the Teatro Porta Romana in Milan and the Teatro Olímpico in Vicenza, and internationally in Tokyo, Paris, Kassel, Munich, Wiesbaden, and the United States.