This is E3 Official... Beyoncé Knowles has revealed the song she'll sing for Barack and Michelle Obama's first dance on inauguration night Tuesday. "I am so honored that I will be performing for President Obama and the First Lady,..." "To sing 'At Last' while they have their first dance is a dream come true," she says. "I could not be more honored and excited that they have asked me to be part of this moment in history." Knowles had been vocal about wanting to be a part of Obama's inauguration. "I'm there. I can't wait," she said in November. "I feel like all of us, we're ready to do whatever we have to do. Whatever they want -- if they need me to volunteer, they need me to sing, I'm there, and I'm ready." Watch Beyoncé's as she covers the Etta James classic 'At Last' below: