At one point during the fascinating new PBS Great Performances special “Broadway Musicals: A Jewish Legacy,” Mary Rodgers Guettel, daughter of famed composer Richard Rodgers, furrows her brow and thinks back on her father’s contemporaries and says, “I’m trying to think if there was anybody not Jewish.”

While there were certainly composers for the Great White Way who were not — notably Cole Porter — the very long list of Jews in the nascent days of the art form is staggering.