The First Lady: Gaga and Tony Bennett serenade the Obamas in SECOND night of partying at bash for White House staffers who burst into song for the President with impromptu rendition of Signed, Sealed, Delivered



Lady Gaga wore a spectacular white dress as she wowed fans with Bennett at the Tuesday night event

The President and First Lady attend two inauguration balls at the Washington Convention Center on Monday



Celebrities revealed in Tuesday morning tweets that the partying continued at the White House until 3am



Guests on Monday included John Legend, Katy Perry, Kelly Clarkson, John Mayer and Alicia Keys

Obama had a dance-off with singer Usher and Michelle danced to 'Single Ladies'






Washington D.C. reverberated to the sounds of partying for a second consecutive evening last night as Lady Gaga headlined a spectacular private event for thousands of Obama staffers.



The singer, who wore a jaw-dropping white Versace dress, sang 'The Lady Is A Tramp' with renowned crooner Tony Bennett at the Washington Convention Center to the delight of those who had campaigned for the President's re-election.



Although no media were allowed into the event, many in attendance took to social media and Instagram to share pictures. Guests revealed they also burst into song by serenading President Obama with an impromptu performance of campaign favourite 'Signed, Sealed, Delivered' as he took the stage.



Before Gaga's breathtaking performance, the President and the First Lady Michelle Obama thanked supporters for their hard work, saying that the thousands of guests at the staff ball represented his 'deepest hopes for America.'

Stars: Lady Gaga wowed throngs of Obama groupies tonight, gracing the stage at the White House staffers' inauguration ball with crooner Tony Bennett

Fired up: First lady Michelle Obama danced in her seat when her husband announced the musicians

Smooth: Lady Gaga received a kiss on the hand from smooth crooner Tony Bennett during the performance for the President and his staffers in Washington



Diva: The eccentric diva wore a meringue-like dress and played on a piano that resembled something out of Star Trek

Tuesday's inauguration festivities came hot on the heels of Obama's Gangnam Style dance off with singer Usher at the spectacular after-party he and wife Michelle threw at the White House on Monday night after attending two glitzy events to celebrate his inauguration.

At last night's event, the final celebration of his inauguration, the President welcomed more than 10,000 guests, including campaign employees and volunteers, inaugural workers, Democratic Party members, and White House officials, saying: 'You all clean up pretty good.'

He continued: 'It makes me know that America's future is in good hands. As long as all of you understand the immense and incredible power that you possess when you work together, when you join voices.'

He introduced his wife, who was dressed in a silver and black ensemble, and referred to her new hairstyle. 'Here's the First Lady, bangs and all, looking very sparkly and twinkly,' he said.



First lady Michelle Obama echoed the President's campaign-year chant of 'fired up, ready to go.' And fired up she was, acting out the president's lines as he spoke and dancing when he announced the musicians.

Welcoming his guests: President Obama, with his wife Michelle, thanked the staffers in attendance for their hard work

No rest: It was the second night in a row the Obamas partied, as they attended two balls and threw a private party on Monday night Enthusiastic: Michelle shouted 'fired up, ready to go' with the crowd, and her husband said she was getting 'a little silly' after the long weekend Thankful: Vice President Joe Biden and his wife Jill also took to the stage to thank staffers who had helped win the campaign Stunning: Jill Biden, who also addressed the crowd of more than 10,000 Obama staffers, looked demure in a blue dress with green flowers



'It's been a long weekend,' Obama said. 'She's getting a little silly now.'

The crowd then serenaded the President and his wife with an impromptu rendition of 'Signed, Sealed, Delivered, I'm Yours,' one of the many campaign theme songs, guests revealed on Twitter.

Lady Gaga thanked the president for standing up for gay rights and dedicated 'Born This Way' to him. She also sang 'Edge of Glory' before Tony Bennett joined her for a duet of 'The Lady is a Tramp,' a track the odd couple first recorded together in 2011.

David Plouffe, the campaign manager for Obama's 2008 bid for the White House, and Jim Messina, the former White House Deputy Chief of Staff for Operations, also addressed the crowds, followed by speeches of thanks from Vice President Joe Biden and his wife Jill.



Proceeds from the ball will go to a memorial fund for Alex Okrent, a campaign worker who collapsed and died at Obama's campaign headquarters in July.

'Alex was one of you,' Obama said of Okrent. 'This incredibly thoughtful, talented, compassionate, caring young person who decided to get involved because he thought he could make a difference. And tragically, he ended up leaving us while working on the campaign... It was heartbreaking. It reminded us of how precious our time on this earth is.'