Born in Canosa di Puglia in Italy in 1931, Marchetti was a key figure in the world of avant-garde composition. In 1956 he met Spanish composer Juan Hidalgo, both of whom met and collaborated with John Cage in 1959.

In 1964 the pair formed the Zaj group, a musical collective heavily influenced by Cage’s thinking. Though the group started out with a musical focus, it soon shifted to included figures like poet and critic José Luis Castillejo.

The Zaj group toured throughout the USA in the 1970s, and though Marchetti disbanded the group in 1993, he continued writing music for several years after that. Most of his early music was released through the Cramps Records label, which issued an exhaustive retrospective of his career last year.

Marchetti influenced several contemporary artists – both Oren Ambarchi and Keith Fullerton Whitman paid their respects to Marchetti on Twitter, with Whitman saying that he was “a crucial mind in contemporary musical thought and action.”

Spain’s El Pais newspaper reports that Marchetti died of a heart attack in Milan. He had been in ill health for some time, suffering a stroke and gradual hearing loss over the past several years.