Antonius Wilhelmus Adrianus de Leeuw (born Rotterdam, 16 November 1926; died Paris, 31 May 1996) was a Dutch composer. He was known for his experiments with microtonality.
Taught by Olivier Messiaen and others, and influenced by Béla Bartók, he was a teacher at the University of Amsterdam and later professor of composition and electronic music at the Sweelinck Conservatory in Amsterdam from 1959 to 1986. Among his notable students are Gheorghi Arnaoudov, Michail Goleminov, Walter Hekster, Tristan Keuris, Liza Lim, Chiel Meijering, Otto Sidharta, and Brian Ferneyhough.
He studied ethnomusicology with Jaap Kunst between 1950 and 1954 [1] and the encounter with the Dagar brothers and Drupad on his first visit to India in 1961 deepened a lifelong interest in "transculturation". He also visited Japan in the 1960s. This manifested itself in his work for Western instruments by the occasional use of microtonality as well as in compositional plans; Gending (1975[2]) for Javanese gamelan is a rare foray into writing for non-western instruments.
He wrote three operas, all to his own libretti, including a television opera Alceste (1963, after Euripides), the one-act De Droom ("the Dream", 1963), and finally Antigone (1989–1991, after Sophocles).