"Johns and Barry are doing the show!"
The classic 42nd Street about the 42nd street dance theatre at Broadway is Lloyd Bacon's film, but everybody knows because of Busby Berkeley and his stunning staging talent and dance choreographies. To know this you won't expect too much from the story - I bet 4 out of 5 movie fans are watching these films because of Berkeley and the damn good music from the '30s.
Thus if you expect some weak, subservient, shallow story you'll have a positive surprise: "It's a musical comedy with dancing" - says Julian Marsh, the obsessed production director (similar character as Roy Scheider's amazing Joe Gideon in Fosse's All that Jazz (1979)) in the film, but the whole is more than a musical within a musical. The story gives insight into the darkest years of the American great depression. The camera almost never leaves the music theatre, but within its walls, within the desperate effort staging a huge show in five weeks, explicitely emphasizing the weight of the show on people's lifes gives extra values to Lloyd's film.
As I said above the film is about staging a 'never seen before' show (Pretty Lady) with the beautiful Dorothy in the leading role. Not I'm the only one who admires her beauty: as it used to be, a rich but old and dumb fan of her sponsors the whole show, and I won't kill the joke if I tell you the source of the suspense: a former lover of Dorothy endangers this "perfect" cooperation between the show business and the sponsor's wallet...
Dorothy is a more than classic beauty of the '30s, but the real eyecandy is the way how the cinematographer (Sol Polito, see more from him here) and Berkeley created the visual style of the film. Actually the camera is training together with the dancers preparing for the show finale (carefully avoiding to show the most exciting angles and settings to reserve them until the end). Very brave camerawork from the lowest to the vertigous heights, optical tricks (sometimes the choreography is able to imitate these caleidoscope-like tricks (see the picture)), moderate cutting (the performances and the dances are more real / the viewer sits in an imaginary perfect position), and so on...
One more thing: Ginger Roger's "mistake" ("bel... tummy") can't be a mistake - see the revealing discussion about it here.
Even if it's a true masterpiece (within its genre!), you should decide about watch it or not yourself. I did and don't regret.
8/10