Country music superstar Carrie Underwood showcased her professionalism and quick thinking at President Donald Trump’s inauguration ceremony on Monday, salvaging a potentially awkward moment with an impromptu a cappella performance. The 60th Presidential Inauguration Ceremony, held inside the U.S. Capitol Rotunda, took an unexpected turn as Underwood awaited her cue to perform “America the Beautiful,” as the track briefly played before cutting out, leaving Underwood to make a split-second decision. “I can just sing it,” she was heard saying to a member of the production team. Addressing the audience, which included Trump, his family, distinguished politicians, and other celebrities, Underwood said, “If you know the words, help me out here.” She then began to sing an unaccompanied rendition of the song….