is an Italian composer. In 1982 he took his diploma in piano (with Maria Golia) and composition (with Gilberto Bosco) at the Turin Conservatory, and in 1983 he graduated in humanities and philosophy from Turin University. He subsequently studied with Brian Ferneyhough (Musikhochschule Freiburg, 1983—6) and Franco Donatoni (Accademia di S. Cecilia, Rome, 1987). In 1984 he was appointed to teach composition at the Turin Conservatory, and from 1999 at the city university as well. He was composer in residence in Berlin, a guest of the DAAD (1998—9).

He worked on music education with Sergio Liberovici whose unfinished opera Malzel he orchestrated with Luciano Berio in 1995. Like Giacinto Scelsi, Castagnoli employs a sophisticated style directed towards timbral inventiveness, and it was to Scelsi that Castagnoli dedicated not only his first orchestral work Klang, but also an analytical essay for the series Quaderni di Musica Nuova which he founded in 1987.