Four years after launching their label The Row, Ashley and Mary-Kate Olsen have nothing to prove. The ready-to-wear is in nearly 150 stores worldwide, and their new bag line, including a crocodile backpack that costs almost as much as a new BMW, is reportedly selling briskly at Barneys. But they impressed again with their latest show. First, the setting: a vaulted-ceiling, wood-paneled studio at the DiMenna Center for Classical Music as serenely lovely as the collection (you can be sure this will become a popular fashion-week venue in the future). Second, the clothes: Spring is more restrained than their super-luxe Fall outing. The palette, mostly white and soft shades of mint and blush pink, played a part in that. So did the silhouettes: long, sleeveless tunics over sheer pants; a printed satin pajama set with a long silk robe over it; an elongated tuxedo jacket worn with full trousers.

The Olsens said their twin inspirations were a Seattle exhibition of Nick Cave's Soundsuits and the country of Tibet. "We wanted everything to float and breathe, or make a sound even," Mary-Kate explained afterward. Tibet came into the picture via the prayer beads slung across the torso of one model and the handmade open-knit sleeves of a sweater. There were echoes of Celine's last Spring collection in the more artisanal bits. As for Mr. Cave? In the stillness of the performance space, the shell buttons densely embellishing a long tank faintly jingled.

Other evening pieces made you sit up and take notice, too—most notably, a voluptuous caftan embroidered with silver and crystal beads at the bodice. That caftan happens to be corseted underneath; no detail goes unattended to here. The workmanship at The Row is exceptional, and the results are as elegant as anything we're bound to see this week.