Entered from booking ledger and New York Times concert listing and review. "CONCERT AND OPERA PROGRAMS." New York Times (1923-), Mar 26 1961, p. 1. ProQuest. Web. 22 Sep. 2022. "ELSA LUDEWIG GIVES RECITAL ON CLARINET." New York Times (1923-), Apr 03 1961, p. 28. ProQuest. Web. 26 Sep. 2022.