Kelly Clarkson sang "My Country, 'Tis of Thee" at the Presidential Inauguration of President Barack Obama on Jan. 21, 2013.
The Grammy-winning pop star and first winner of "American Idol" attended the event with her fiance, Brandon Blackstock (see photos of them and other celebrities at the ceremony).
"Wow ....I was incredibly nervous and cold ha!" Clarkson said on Twitter. "I just wanna officially thank President Obama for opening for me haha! Just kidding :)"
Beyonce, a longtime supporter of Obama, also sang at the event -- she performed the national anthem (watch video). Clarkson later posted a photo of herself with the singer, Tweeting: "Me and B just hangin' out ....don't worry about it. Seriously, God did good. She is so beautiful!"
Other stars who attended included actresses Eva Longoria and Kerry Washington.
Watch a video of Kelly Clarkson performing "My Country, 'Tis of Thee." What do you think about her performance? Vote in our poll.