Manhattan (Woody Allen, 1979)
The opening of this film is just wonderful and performs a kind of representative feat for Woody Allen: it moves very subtly and swiftly from straight comedy (construction workers look at a walking woman while Allen narrates that behind his glasses can be found the sexual prowess of a jungle cat) to something quite beautiful: the end of the sequence, with ‘Rhapsody in Blue’ and the fireworks, actually gives me chills.
(You can see it here, but it’s not well-served by YouTube compression).
