As Thousands Cheer: 2the Life of Irving Berlin

``Alexander's Ragtime Band,'' ``God Bless America'' and ``White Christmas'' are among some 1500 songs written by Berlin, a Hollywood tycoon who remained reclusive and insecure despite his popularity. ``Berlin's story, richly and skillfully told here, is not only the story of popular American music . . . but approaches being the story of 20th-century America,'' said PW. Photos. (July)