AceShowbiz -

Former U.S. president Bill Clinton unknowingly photobombed "American Idol" winner Kelly Clarkson as she was getting ready to perform the patriotic song "My Country 'Tis of Thee" at President Barack Obama's inauguration ceremony on January 21 in Washington D.C. In a picture and during televised broadcasts of the event, a wide-eyed President Clinton was captured leaning to the side seemingly to get a better look at Clarkson. The picture has now circulated online.

Clarkson didn't address the Clinton photo and instead posted a snapshot of her shaking Pres. Obama's hand on her Twitter account. "Maybe the coolest photo I've ever been in ....ever :)," she said. "What an honor to be a part of history!" the Grammy-winning singer tweeted. "Obama's presence was powerful and his words unforgettable. It's a proud day for America!"

Clarkson confessed to being "incredibly nervous and cold" during her performance at the inauguration but said she was honored to be part of the historic occasion. It didn't show at all as she gave a rousing rendition of "My Country 'Tis of Thee", belting the song without flubbing the lines and hitting all the right notes, delivering it impressively until the end.

Any other musical act would be similarly anxious even with the caliber as that of Clarkson, or Beyonce Knowles and James Taylor, who also performed during the inauguration ceremony. They sang in front of nearly one million spectators and in such a momentous event.