If you can push past the flag-waving, this Warner Brothers effort from 1942 is a superior entry in a dubious genre, the musical biography. Michael Curtiz’s direction is supple and intelligent, but what makes the movie is James Cagney’s manic blur of a performance. As George M. Cohan, the Broadway star and songwriter, Cagney is able to exploit both his dramatic and dancing abilities; he makes Cohan into such a dervish of nervous energy that he almost gives off smoke. For once there is some real interest in the dramatic passages, which go so far as to suggest that Cohan wasn’t a pleasant man to live with. With Walter Huston, Joan Leslie, Rosemary DeCamp, and Frances Langford; photographed by James Wong Howe.