Yiddish theatre consists of plays written and performed primarily by Jews in Yiddish, the language of the Central European Ashkenazi Jewish community. The range of Yiddish theatre is broad: operetta, musical comedy, and satiric or nostalgic revues; melodrama; naturalist drama; expressionist and modernist plays. At its height, its geographical scope was comparably broad: from the late 19th century until just before World War II, professional Yiddish theatre could be found throughout the heavily Jewish areas of Eastern and East Central Europe, but also in Berlin, London, Paris, Buenos Aires and New York City.

Sigmund Mogulesko — Yiddish: זעליק מאָגולעסקאָ Zelik Mogulesko, first name also sometimes spelled as Zigmund, Siegmund, Zelig, or Selig, last name sometimes spelled Mogulescu — was a singer, actor, and composer in the Yiddish theater in New York City. He was born in Kalarash, Bessarabia and began singing in the local synagogue choir. Before reaching adolescence, he was paid nearly three times what teachers made, to sing in the synagogue of Chişinău. Soon after moving to Bucharest, Romania, he was paid to sing in churches as well as synagogues, and started acting.