Ernst Lubitsch's Angel 1937

If Angel invokes Pirandello as The Shop Around the Corner evokes Molnar, it is because Lubitsch taught the American cinema the importance of appearances for appearances sake (Pirandello) and the indispensability of good manners (Molnar).
--Andrew Sarris

It took me some time to appreciate Lubitsch, the most subtle and elegant of directors, who brought a not-always-appreciated European sensibility to American films.  His films were often comedies or musicals with flair, usually taking place outside the United States.  Angel takes place in a bordello in France and a country house in England with three main characters: Lady Maria Barker (Marlene Dietrich), Sir Frederick Barker (Herbert Marshall) and Anthony Halton (Melvyn Douglas).  Maria and Anthony are looking for excitement when they meet in Paris and have a brief fling, without Maria revealing her identity.  It turns out that Anthony and Sir Frederick are old army buddies and meet in London, when Anthony finds out who "angel" really is, though she won't admit it.  Maria returns to Paris to meet Anthony but finds her husband there also; for the first time Maria realizes how much her husband actually cares about her and leaves with Sir Frederic in a distinctly not-happy ending.

Angel is not a comedy, though there are comedic elements (especially among the servants, who emphasize proper dress and good manners) but rather a tragedy of marriage, just as Lubitsch's Broken Lullaby (1932) is a tragedy of war.  The Barkers are quite mismatched, sleeping in separate bedrooms and tolerating each other's passions:  Lady Barker loves the opera while Sir Frederick is devoted to diplomacy and horse racing.  Lubitsch started out as an actor and director in silent films and knows how to tell a story with a minimum of dialogue, by facial expressions, camera movement and placement, starting with a tracking shot outside the windows of the bordello and encouraging us to use our imagination when doors are closed to us.