An elegant second Obama inauguration, packed with high-fashion, high-energy and high-profile stars, twirled to an end Monday as President Obama and first lady Michelle Obama — she in another stunning gown — danced the night away at the inaugural balls.

And it's a gown by Jason Wu, the same designer who crafted her 2009 white inaugural gown. The White House said this one is custom-made, ruby red, sleeveless, backless, cinched at the waist, chiffon and velvet, flowing pleats falling to the floor, with a handmade diamond-embellished ring by jewelry designer Kimberly McDonald. She is wearing shoes by Jimmy Choo. And her hair was down in her new style with the bangs everyone has been talking about.

The initial reaction on Twitter was positive, and congratulations poured in for Wu. But there was surprise, too, especially from Wu. "#Inshock!!!" he tweeted.

"I can't believe it. It's crazy," he told the Associated Press from his Manhattan studio as he was trying to share the news with his parents in Taiwan. "To have done it once was already the experience of my life. To have a second time is tremendous."

"I was gobsmacked" given Mrs. Obama's tendency to spread her fashion benedictions around, said fashion columnist Robin Givhan on CNN. "In some ways it was a bit of a safer choice. There's so much pressure on an inaugural gown to be an extraordinarily symbolic dress that she felt safe going back to someone who had done right by her."

As singer Jennifer Hudson crooned Al Green's Let's Stay Together, the president and Mrs. Obama began to dance, first with each other and then with other military guests at the Commander-in-Chief's Ball.

Earlier, one of the first performers at the Commander-in-Chief's Ball for members of the military was Brad Paisley, in his customary cowboy hat and rocking the rafters.

At one point, he joked, "Our democracy is the envy of the world and tonight we celebrate by getting drunk in a convention center." After he finished his set, he told the audience, "This was an honor! Stay safe out there!"

Then Alicia Keys, in a clingy tomato-colored dress, sang an adaption of her top-selling This Girl's On Fire as "Obama's On Fire."

Fun. later took the stage, but the joint really began hopping when Stevie Wonder swung into They Can Feel It All Over as his backup horn section blared. Even on the TV screen you could see the scores of smartphone cameras held up from the crowd. Later, Marc Anthony sang a love song in Spanish.

The White House pool at the ball reported that most men in the room were wearing dress uniforms and most women were in gowns. But there are plenty of women in their uniforms, wearing knee-length skirts or pants.

The room is lit in purple with orange spotlights roaming around, the pool reported.The backdrop of the stage is mostly blue, with a big presidential seal at center and white curtains on either side.

The president, who says he likes his wife's new hair style, introduced by recounting what he jokingly said at the congressional lunch earlier in the day. "Some may dispute the quality of the president but no one disputes the quality of the first lady," he said.

The Obamas did not dance the whole night; it had been a long day. Besides, it's always too crowded to dance much at presidential inaugural balls. The larger ball was packed to the gills, with little room to move around, let alone dance. At the larger ball, some 35,000 guests were expected to fill the Washington Convention Center to watch the presidential couple's pas de deux.

Also watching the couple this weekend: a passel of performers and stars, such as Beyoncé, Alicia Keys, Kelly Clarkson and Katy Perry, Stevie Wonder, Smokey Robinson, Usher and John Legend. Also, Black Violin, Far East Movement, fun., members of the Glee cast, and Soundgarden were keeping the party-goers entertained on multiple stages at the convention center.

Beyoncé, who sang At Last for the couple's first dance at the 2009 inaugural balls, this time sang a passionate national anthem to conclude the ceremonies on the Mall. Clad in a black Pucci dress, her highlighted hair loose on her shoulders, glittering emerald earrings in her ears, she came very close to matching the late Whitney Houston's thrilling 1991 Super Bowl rendition of the notoriously difficult-to-sing song.

"Wow," exclaimed master-of-ceremonies, New York Sen. Chuck Schumer, D-N.Y., when Beyoncé was done. Fans-in-chief FLOTUS and the president kissed and hugged her.

Meanwhile, at the Creative Coalition Ball, liberal Hollywood's fundraising gala and celebration of the Obama re-election, a contingent of boldfaced names made their way down the red carpet into a downtown Washington arts center, to be entertained by headliner The Goo Goo Dolls.

And yes, even Academy Award winners get awestruck by the atmosphere and the rituals of America's democracy. "My favorite (moment) was to be standing outside with all my fellow Americans. It was a very moving speech. I didn't know I would be moved and in fact I was," said Oscar winner Melissa Leo, clad in Ralph Lauren.

Evan Handler, Charlotte's better half on Sex and the City, praised Obama's oratorical skills. "It's great. It was a good speech today," he said, adding that he's been a longtime member of the Creative Coalition. "I was last with them at the Republican National Convention so this is a very different atmosphere."

The inaugural weekend started Saturday for the Obamas and reached a crescendo Monday morning when the family, including daughters Malia, 14, and Sasha, 11, stepped out of the White House and headed to a nearby church for an Inauguration Day service.