This classic is fine entertainment with plenty of everything - humor, singing & dancing, good writing, and lavish sets and costumes. The only thing missing is a plot, but too much story might have taken attention away from everything else that makes "Top Hat" enjoyable to watch.
Fred Astaire and Ginger Rogers are talented and charming as a somewhat star-crossed couple. The whole story line is that Ginger thinks Fred is someone else (who is married instead of single) and thus misinterprets and rejects his advances. Their many abilities and a fine script make this paper-thin plot seem not only acceptable but amusing. Edward Everett Horton is both funny and indispensable as Fred's friend (and the man whom Ginger thinks Fred is), and the rest of the supporting players are also quite good.
This is the kind of carefully produced classic that offers many reasons for watching - see it if you have the chance, whether or not you usually like musicals.