Entered from booking ledger and New York Times concert listing and review. "CONCERT AND OPERA PROGRAMS FOR THE WEEK." New York Times (1923-Current file), Mar 10 1957, p. 1. ProQuest. Web. 17 May 2021. "Margaret Baetz Offers Recital." New York Times (1923-Current file), Mar 12 1957, p. 39. ProQuest. Web. 17 May 2021.