Astaire can't do anything bad. - Fred Astaire

Grayce Llewellyn thought that with appropriate dietary restrictions, she and J Sheringham Adair could have Ivor Llewellyn looking like Fred Astaire.

The major difference between Astaire and Kelly is a difference, not of talent or technique, but of levels of sophistication. On the face of it, Kelly looks the more sophisticated. Where Kelly has ideas, Astaire has dance steps. Where Kelly has smartly tailored, dramatically apt Comden and Green scripts, Astaire in the Thirties made do with formulas derived from nineteenth-century French Farce. But the Kelly film is no longer a dance film. It's a story film with dances, as distinguished from a dance film with a story. When Fred and Ginger go into their dance, you see it as a distinct formal entity, even if it's been elaborately built up to in the script. In a Kelly film, the plot action and the musical set pieces preserve a smooth community of high spirits, so that the pressure in a dance number will often seem too low, the dance itself plebeian or folksy in order to "match up" with the rest of the picture.

Fred Astaire is the best singer of songs the movie world ever knew. His phrasing has individual sophistication that is utterly charming. Presumably the runner-up would be Bing Crosby, a wonderful fellow, though he doesn't have the unstressed elegance of Astaire.