Zaj was an experimental music and performance art group formed in 1959 in Milan, Italy by composers and intermedia artists Walter Marchetti and Juan Hidalgo with the support of the American composer John Cage. The group received major contributions by different artists from the Spanish avant-garde scene, notably from the writer and diplomat José Luis Castillejo and from the interdisciplinary artist Esther Ferrer. During the 1960s, members of Zaj took part in different Fluxus events organised by George Maciunas. With the help of John Cage and his agent Mimi Johnson, Zaj also toured in different cities in the United States in the late 1970s. The group was disbanded in 1993 by Walter Marchetti.