Ever since the trailer appeared last summer, the release of “Cats” has been anticipated the way one anticipates the opening of a can of Fancy Feast Classic Paté: Could the film really be quite so, well, aromatic? It takes some time for a solid payoff, but finally Jennifer Hudson’s tragic Grizabella launches into her reprise of “Memory,” with all the agonized, heroic, even operatic ornamentation the song has never warranted. And if you manage not to laugh at that point, give yourself a belly rub.

Mostly, “Cats” is a confusing...