Unfaithfully Yours (1948)

In a search for a filmmaker who we like as much as Ernst Lubitsch, Preston Sturges was recommended.  He is known for his witty movies with a hint of slap stick, which does sound a lot like Lubitsch.  The dialogue drives the movie and as a result, there is little that actually happens.
The movie spends most of the time inside the obsessive imagination of its protagonist, an easily excitable and completely self-centered concert conductor . He at first resists the idea that his wife might be unfaithful to him, refusing to look at a private detective, and then his subsequent pathologically jealous state adds vitality to his art. Played by Rex Harrison, the conductor’s mind becomes the stage on which the film’s fantasized events play out, ranging from elaborate traps to the slashing of a razor, from a humble goodbye to Russian roulette. Under the false impression that his faithful and loving wife is cheating on him, he directs his orchestra, and as he does so, he loses himself in the particular mood of the given composition. In a flurry of impassioned emotion shaped by selections from Gioacchino Rossini, Richard Wagner, and Pyotr Ilyich Tchaikovsky, he visualizes himself in a series of sometimes vengeful fantasies. Sturges explores the notion that music not only shapes our mood but that our perceptions of the world are rarely accurate.