Night of the Supermodels in New York, Guest Appearance by Rihanna

It takes a lot to distract from Rihanna. Especially when she enters a room wearing a cleavage-spilling corset underneath a cream net gown with hundreds of seed pearls caught in its web, sits next to Liv Tyler and starts whispering in her ear.

It takes a lot to upstage a mini-reunion of supermodels: Stephanie Seymour in leopard, hugging Naomi Campbell and both of them air-kissing Linda Evangelista, as Amber Valletta, all in black, smiles benignly at the scene.

Yet that is exactly what Pieter Mulier did Friday night with an Alaïa show at the Guggenheim Museum that redefined chic in audience, venue and style. After three years of negotiating, not always easily, with the heritage of the house Azzedine built, he finally made it his own.

Holding the first fashion show to make use of the entire spiraling Frank Lloyd Wright ramp twirling up to the museum’s domed glass ceiling, Mr. Mulier sat his guests — an idiosyncratic mix of gallerists, artists, photographers and fashion folk — on round settees on the ground floor, and then sent the models strolling from top to bottom. At first all the audience could see as they craned their necks back were little heads, bobbing along just above the uppermost part of the ramp. Then shoulders. Then perhaps a torso or two.

Finally, the whole thing: a collage of spirals and geometry, form and function that took the essence of sportswear and made it modern. Skin-toned bandeaus were paired with classic Alaïa skater skirts, but rendered lightly in layers of silk chiffon, and billowy trousers that looked like a cross between harem pants and sweatpants (harem sweats?). Later, panniers were added at the hips, as if they had been crossbred with a ball gown and recast in silk taffeta.