Hearing David Ehrenstein and others rave over Charles Walters made me rent this one. It's a surprisingly heartfelt little joy, a romantic comedy full of passion, betrayal, disillusionment, heartbreak that still manages to be a first-rate musical (or maybe I have that upside-down--it's because it's a musical that it manages to cram all that passion, betrayal, etc., etc. in there).
A few notes: When Ann Miller dances with Astaire to "It Only Happens When I Dance With You," the song is sensual, eloquent in heat and body language. When Judy Garland reprises it later to Astaire on the piano she sings with plenty of passion as well, but it's a different kind of passion--soulful, trembling, vulnerable. Walters has the camera approach the two lovers slowly, discreetly, as if he knows he's moving in on a very private moment and doesn't want to disturb them; the shot stops in time for Garland, who finishes the song, to throw Astaire a look of total emotional nakedness, as if to say "This is me; this is what I am. So what do you think?"
I can't think of anyone else who can act with his back as well as Astaire does in this scene (he's facing away from the camera the whole time): the arch of his back, the tilt of his head, the slightly lifted chin suggests ever increasing levels of adoration--he even manages to show us a bit of his brow, wrinkling. His response to Garland's look is just about perfect.
That's about it, except "Steppin Out With My Baby" has (aside from the otherwise tremendous dance numbers, sometimes featuring only Astaire and a walking cane--Astair at his best, in my opinion) an eerie moment where Astaire spins and leaps and bounces his cane off the floor, catching it on the crook of his arm, all in slow motion while the rest of the dancers are stepping in normal time, yet both dancers and Astaire move in time to the beat--a feat I'm sure was a bitch to achieve, in the days of primitive sound recording, special effects, and no computers.