This program brings to life the words and music of the American Yiddish theater. The story's lead characters -- Bessie and Boris Thomashefsky -- also happen to be the grandparents of San Francisco Symphony music director Michael Tilson Thomas. Bessie and Boris emigrated to the United States from Eastern Europe in the 1880s, and while still in their teens, they began to play major roles in the development of New York City's Yiddish theater. For Jewish immigrants who settled on the lower East Side of Manhattan, the Yiddish theater was central to their lives, and provided a stage for the new ideas that were shaping the transition to an American way of life. In "The Thomashefkys," Tilson Thomas serves as guide through the lives and repertoire of his grandparents. Performed at the New World Symphony's Frank Gehry-designed home in Miami, Tilson Thomas shares the stage with a 30-piece orchestra and ensemble cast to bring the repertoire and words of Bessie and Boris to life. With time, aspects of klezmer and cantorial sounds became more integrated and more American, as Jewish composers became immersed in their new surroundings, greatly influencing composers like Irving Berlin and George Gershwin.