What opera starring Mary LeSawyer had its premiere in Philadelphia in 1946?
Mary LeSawyer:  She notably took part in the company's celebrated 1960 national tour, performing in four American operas: ""The Ballad of Baby Doe", "Street Scene", Susannah", and "Six Characters in Search of an Author". Street Scene (opera):  Written in 1946 and premiered in Philadelphia that year, "Street Scene" is based on the Pulitzer Prize-winning play of the same name by Rice.
Street Scene