Robert McFerrin, Baritone, and Salvador Ley, Pianist-Composer Concert of South American Music to commemorate Pan-American Day Entered from booking ledger and New York Times concert listing and review. WORLD PREMIERE of Salvador Ley's DANZA EXOTICA "CONCERT AND' OPERA PROGRAMS OF THE 'WEEKI." New York Times (1923-Current file), Apr 19 1959, p. 1. ProQuest. Web. 5 Aug. 2020. Briggs, John. "M'FERRIN AND LEY IN JOINT RECITAL: BARITONE SINGS SETTINGS BY GUATEMALAN PIANIST OF 5 ENRIQUE MARTINEZ TEXTS." New York Times (1923-Current file), Apr 20 1959, p. 35. ProQuest. Web. 5 Aug. 2020. joint recital 1959-04-19T20:30:00