"His whole thing is lifestyle and he really wants the brand to reflect, as it does, his lifestyle and his friends' lifestyle," Jim Moore, the creative director of GQ, told The Observer. Mr. Moore was talking about Rocawear's spring line. He was standing in a room across the hall from the music, where 25 mannequins were arranged on a stage to display the clothes. "That's the main point that he wants to get across," he continued. "These clothes are really near and dear to him. He's a suit man, but he loves the casual on the weekend."

Most of the mannequins were dressed in some variation of blue jeans and an open button-down layered over a T-shirt. One outfit included a camouflage pullover; another gold lamé. "Sometimes I think it's easier to go to fashion shows in Europe because you're just there to do it," Mr. Moore continued. "And here we have so many assignments going on." He said Jay-Z was finishing up dinner next door. Mr. Moore was planning to leave the party early to supervise a late-night photo shoot for the magazine.

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In the hallway between the two rooms, a pair of waiters in matching vests and ties marched back and forth, shuttling empty champagne flutes. Men in dark suits with gelled hair and ear pieces poked their heads into both rooms and paced between the entrances. Two tall girls in black rompers primped each other and asked the GQ house photographer to take their photo. Another tall girl walked over to a GQ publicist and asked, "Who am I handing celebrities off to?"

Adrian Grenier arrived carrying a camera and began chatting with reporters. A squat man stood at his side punching on a BlackBerry. A publicist? No! A reporter for The Wall Street Journal. They were working on a story together.

Jay-Z was close behind and everyone holding a camera, including Mr. Grenier, rushed towards him.

Mr. Grenier took pictures of Jay-Z, and the other photographers took pictures of that. Then Mr. Grenier turned the camera around and, with outstretched arms, took a picture of himself with Jay-Z. The other photographers took pictures of that, too.

"What you got there, a little hobby or something?" Jay-Z asked Mr. Grenier. Mr. Grenier smiled big. "You have a great night, man," the rapper added.

"You too" said Mr. Grenier. "Good Luck. I know you don't need it. Confidence! You've got it."

Jay-Z looked at him through his sunglasses. "I was going to say the same thing to you," he said. He turned away and strolled into the room with the mannequins.

A photographer anxiously asked him to stand in front of the display. "Don't move me around, big man," Jay-Z said quietly, his hands in the pockets of a black Dior suit. "I like to do it naturally." He leaned against a bar at the front of the room.

"I missed the whole thing, to be honest with you," Jay-Z told The Observer. We were talking about Fashion Week. "I don't want to, uhh, be over here under false pretense." His voice sounded fragile, and he scratched at his shoulder through his white, open-collar shirt. For the last two nights he was performing at Yankee Stadium around this hour.

He started talking about the clothes. "We were known for one thing," he said. "You know the whole thing of what people call urban fashion, which I think is a dirty word these days, but you know whatever." He recalled a time when the Rocawear brand name appeared in large letters on all of its shirts.

"Now my Dior suit don't have a big D on it," he added.

"People listen to all different sorts of music. People are inspired by all different walks of life and culture. It just is what it is. For people to try to put it in these segments, I don't think that's fair," he said. "Like people saying I couldn't play Glastonbury all over again. It's back to that again, you know what I'm saying. Or rap can't play Yankee Stadium. If we subscribe to the notion that people put in our mind, you know, 'Why is it that Rocawear can do an event with GQ?' — quote  unquote, like, this urban brand."

The Observer asked if he wanted Rocawear to start making suits.

Jay-Z paused to think. "I don't know. I don't know. Maybe," he said. "It's like that Kanye line: 'Dressed smart like a London bloke, before he speak his suit bespoke.'"

He said he was glad that his rap colleagues were showing interest in high fashion instead of basketball jerseys. "Sometimes when you turn the faucet on and it overflows onto your floor you should turn it off," he said. He laughed deeply. "It's like common sense. The water! It's getting on my fuckin' floor!"

Were those patent-leather boat shoes he had on?

"Yeah! Well, they're not boat shoes, but they're like more rounded," he said. "They're kind of like suede in the front. Bottega! Bottega!"

His shoes had shiny black trim and braided leather laces. What did it feel like to wear shoes such as these, we wondered.

"They're very..." Jay-Z removed one of his shoes and bent the sole to show us how flexible it was. He was wearing dark socks covered in tiny paislies. "Would you like to try them on?" he asked The Observer.  "What size you wear?" Eleven and a half. "Alright, well you're not going to bust these open," he said and slipped the loafer back onto his foot.

He turned to take a few questions from a New York Post Page Six reporter. "I put my jeans, after I take them off, back in the closet," he said. "I'm telling you, I'm not even joking. I think we make the best jeans period. I think it's comparable to any American brand." A reporter for Women's Wear Daily asked if Jay-Z thought Rocawear would be like Levi Strauss in 150 years. "I hope so," he said. "That's the goal. Hopefully, you know."

Enough questions, right? "Yeah, it's going down now," he told The Observer on his way out of the room. "Champagne hour." But first a toast!

Jameel Spencer, the chief marketing officer of Rocawear, grabbed a microphone and spoke over the room. It was full of people by now. "We're not selling clothes, we're selling a lifestyle," he said. Everyone eyed the mannequins.

"Sell that shit!" Jay-Z yelled.

Mr. Spencer asked everyone to raise a glass. Everyone did, except for Jay-Z. He didn't have one, and he looked around sheepishly. A woman standing next to him handed hers over, and then everyone drank.

Jay-Z put his glass down and made some small talk with a female friend before leaving the room. "I like your hair," he said. "It's like baby hair."

He made his way across the hall towards the music. Kanye West was waiting for him on a couch facing a circular stage in the center of the room. Mr. West was wearing a black suit with a black bow tie and sunglasses. Jay-Z poured himself a glass of champagne from a bottle on the table and sat down at his side.

Once the room was filled, the roof above the stage slid back to reveal the night sky. Trey Songz, a young rapper who used to open for Jay-Z on tour, took the stage.

"Ten years ago, a single was a dream for me. Jay-Z was on the cover with a Rocawear jean jacket that was like a 4x," Mr. Songz said, turning to face Mr. West and Jay-Z's table. It was unclear which cover he was talking about. "It was definitely a 4x. I say that to say that we've all come a long way tonight. Let's do it." His band started to play.

The first song in his set was slow. The second song in his set, "Say ahh," was faster.

"Go girl, it's your birthday. Open wide, I know you're thirsty," he sang. "Say aah. Say aah."

When he was finished with the song's lyrics, Mr. Songz told his band to keep the beat going.  He turned again to the table where Mr. West and Jay-Z were sitting. "Let me see that bottle of Ace," he said. He reached over and grabbed a magnum of champagne.

Mr. Songz carried the bottle across the stage to a busty blonde girl in a black blouse. "Your glass looks empty," he said into the microphone, looking down at her. "Here, give me that." He reached down to take her glass and placed it to the side. His drummer was still playing.

"If you stand in the front, you're gonna be part of the show," Mr. Songz said. "Say ahh." Mr. Songz bent over and the girl stuck out her tongue so he could pour champagne into her mouth. He tipped the bottle for three seconds, and some champagne dribbled down her chin. She grabbed her throat and looked up in surprise. There was a round of applause.

Mr. Songz launched into his final number, "Bottoms up." "Throw ya hands up," he sang. "Tell security we about to tear this club up. Bottoms up, bottoms up."

zturner@observer.com / @zekeft

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