1906. Father is off to the North Pole with Admiral Peary. Leaving New York Harbor, he passes a ship teeming with immigrants, including the Jewish Tateh and his daughter. Back home in New Rochelle, Mother takes in an indigent Black woman and her baby; the woman’s pianist lover soon comes calling in a Model T. So swirls the melting-pot plot of Stephen Flaherty, Lynn Ahrens, and Terrence McNally’s 1996 musical “Ragtime,” adapted from E. L. Doctorow’s impressionistic 1975 novel about the dawn of twentieth-century America. Lear deBessonet’s kinetic revival conjures the churn of the times and their emotional reality. Over a century later, that reality—hope, horror, dizzying uncertainty about the future—hasn’t gotten any less American.—Dan Stahl (Beaumont; through Jan. 4.)Dance