Giambattista Valli has a distinctive advantage as a couturier: He is utterly intimate with his clientele. Age-group 28 to 38, spring chickens in the couture sorority, and innocent of the traditional iconography of alta moda. Which means Valli is able to toy with tradition in a way that seems entirely fresh to his women. In the past, that has meant a soupçon of déjà vu for everyone else, but by some fortunate alchemy, the collection he presented tonight took those antique Roman codes, twirled them around, and deposited something old-but-new on the catwalk. Maybe all it took was basic black and white. Valli opened with a coat-dress in big-cat spots, followed through with a jacket and skirt ensemble traced in black, and consummated the monochrome with a tulle-shrouded black shift clasped at the waist with Luigi Scialanga’s twist of metallic feathers. That statement of intent resonated through the first half of the collection, producing outfits as striking as a croc-collared black shift with an inky squelch of sheen trailing down its front, and an ocelot-spot jumpsuit with an overlay of mousseline that trailed away dramatically.

But then Valli surrendered to the translucence of porcelain under light, and the couture-friendliness of flowers, and the show got terribly diffuse. It was still fine, however, because the designer’s fixation on silhouette guaranteed rigor and movement. His baby infanta dresses (the volume swollen in the front) were all about forward momentum. You’d scarcely expect a collection like this to communicate a spirit of urgency, but there is something about Valli and his girls that says “live for today.” And the thought of them doing that living in these dresses is weirdly appealing.