Playwright, composer, actor, director, and producer George M. Cohan looms large in musical theater legend. Remembered today for classic tunes like "You're a Grand Old Flag" and "Give My Regards to Broadway," he has been called "the father of musical comedy," and his statue stands in the heart of the New York theater district. Cohan's early twentieth-century shows and songs captured the spirit of an era when staggering social change gave new urgency...