L'amour chante et danse

They don't get much better than this: Astaire with the drop dead dancing cool, and Crosby with the honey crooning, both competing for the same gal. Crosby decides to let it all go and settle in the country, then on a whim realizes he can open his country house as a club open on holidays only. The girl he ends up drafting for the floor shows ends up being the love of his life, and the dancing partner Astaire has always been searching for.

Astaire, Crosby, and Reynolds have great chemistry together: I thought it quite convincing how Crosby's overprotective zeal scared Reynolds away for a while, and Astaire was very cool and believable as a kind of an inoffensive opportunist who exploits Crosby's passionate responses to whatever threat he perceives in Astaire.

Top it off with many of Irving Berlin's best classic tunes, performed in interesting interpretations, and you have a very good musical film.