Plenty of great female actors have starred in romantic comedies. Usually if they want to win an Oscar, however, they have to reach for more serious roles. The late Diane Keaton, who died unexpectedly this week, followed a reverse trajectory and made it look disarmingly natural. Her first major film role was in The Godfather, about as serious an American masterpiece as has ever been made. But that same year, she reprised the part of Linda, the object of a nerdy hero’s affection, in a film adaptation of Broadway’s Play It Again, Sam. (Keaton originated the role opposite playwright Woody…
