The "XO" singer, 32, who also performed at President Obama's inaugural ball in 2009 and second inauguration in January 2013, joined a bevy of performers at what is being called a White House "dance party" for the first lady's big 5-0.
The top-secret celebration hosted about 500 guests sprinkled with A-listers of the political and celebrity variety: Bill and Hillary Rodham Clinton, recording artists Stevie Wonder, Paul McCartney, Smokey Robinson, James Taylor, Gladys Knight and Herbie Hancock, jazz singer Ledisi, Oprah's bestie Gayle King, actor Samuel L. Jackson, NBA legend Magic Johnson, former Olympic figure skater and current State Department senior advisor Michelle Kwan, TV host Rachael Ray and the "Today" show's Al Roker and his wife, ABC correspondent Deborah Roberts, were also among the guests, according to the Washington Post and "Today."
Ledisi, a Grammy winner, opened the evening's live performances, and Beyonce took over for about a 30-minute set accompanied by a full band, Us Weekly reported. Singer John Legend also sang "Happy Birthday" and was accompanied by his new wife, Chrissy Tiegen. DJ Cassidy took over musical duties following the live performances, the magazine said.
Beyonce wore a revealing cocktail dress for the occasion and shared more than a dozen photos of her visit to the White House along with daughter Blue Ivy Carter, who posed with a White House Christmas tree and played with the Obamas' dog Sunny. She brought her mother, Tina Knowles, and sister Solange Knowles to the event. (As for husband Jay Z, it's unclear if he was there too, but on Sunday it was reported that the husband-wife duo would be performing together at Sunday's Grammy Awards in Los Angeles.)
Bey reportedly sang "Single Ladies (Put a Ring on It)" and "Irreplaceable," and Wonder gave an impromptu performance of "Signed, Sealed, Delivered" and "Do I Do," the Chicago Tribune said.
Though the White House has yet to comment on the affair, which was closed to the press, an invitation to the event leaked back in December indicated that the theme would be "Snacks & Sips & Dancing & Dessert" and advised guests to bring dancing shoes and to "eat before you come," according to the Tribune.
Guests were told not to bring their cellphones into the gala and were provided with a check-in area for their devices. "No cellphones, no social media" signs were said to be posted at the party, the newspaper reported.
The evening was "literally a house party that happened to be at the White House," Roker told the "Today" team on Monday by phone. "Sasha and Malia had invited a lot of their friends, so there were a lot of young people."
The president is said to have given a heartfelt speech about his wife, calling her a great mother and wife and saying that she made him a better man, sources told the Tribune.
Michelle Obama was said to have worn a flowing red blouse and pants and to have danced frequently during the affair.
"We had such a good time with the 1st family in dc tonight ! Now on to the next stop !" singer Jennifer Hudson wrote on Instagram, captioning a photo of herself all dressed up with fiance David Otunga.
The first lady's birthday was Friday, and she took to Twitter to share her thoughts on the landmark.
"Excited to join Barack in the 50+ club today… check out my @AARP card! –mo," she tweeted from the FLOTUS Twitter account, sharing a photo of her membership card.