"It was woman as dandy," declared Tom Ford of the sinuous twenties and thirties feel he melded into satins and chiffons for YSL's Spring collection. The designer narrowed and lengthened Saint Laurent's original boxy, hard-edged lines, opening with louchely draped powder-blue satin suits. The jackets closed with wide hip fastenings over a new-shaped pant that was cut loose to the knee, then caught tight with rows of tiny covered buttons.

Ford's skew on House retro synthesized masculine and feminine elements: a low-belted, gold-buttoned trench was paired with rib-cuffed jog pants, while petaled jersey skirts flew out from under skintight black leather jackets. Reruns of the classic smokings included tuxes, white vests, and mannish dressing gowns, cut floppy and liable to fall open at the breast at any moment. Together with the major frizzed hairdos and sexy high-heeled spectator shoes in leather and canvas, it added up to a new silhouette for the tall, sexually-in-control woman Ford envisions as the spirit of modern YSL.

She's just as powerful-looking in a dress, of course. Karen Elson (who, with her alabaster complexion and ginger hair, is making a comeback as the perfect pre-war muse this season) symbolized that strength, striding out in palest pink bias-cut jersey, pieced in a twenties diamond-pattern at the hip and with handkerchief points flying from shoulder and hem. There followed a line of equally individual gowns in satin and chiffon, worked with curving scalloped layers and plissé skirts and held up by the finest shoulder straps.

The visions of pared-down, re-imagined Deco glamour kept coming. There were more sober options in black, with strands of jet beading moving over dark georgette, but they were finally upstaged by a sensational misty blue chiffon gown, delicately suspended from strings of crystal and swinging sparkling fringe, and a white dress smothered in gold coins with delicate pleats fanning out in the skirt. The details in this deluge of gorgeousness were equally unmissable: the new horn-handled pony-skin bags, and the enticingly luxe diamond jewelry. That turned out to come from Boucheron, not YSL—but since they are sister companies in the Gucci Group, it made for a clever piece of borrowing.