Entered from booking ledger and New York Times concert listing and review. Wagner's "Siegfried Idyll" does not appear in the concert listing, and the review does not mention the Schoenberg Chamber Symphony, so it is possible there was a program substitution of one for the other. NEW YORK PREMIERE of Mario Davidovsky's NONETO "THIS WEEK'S CONCERT AND OPERA PROGRAMS: CONCERTS, OPERA AND RECITALS." New York Times (1923-), May 19 1963, p. 1. ProQuest. Web. 29 Sep. 2023. "CITY CHAMBER GROUP IN 'SIEGFRIED IDYLL'." New York Times (1923-), May 26 1963, p. 92. ProQuest. Web. 2 Oct. 2023.