It was a big day for President Trump, and almost as big for Carrie Underwood and Lee Greenwood, two country stars invited to perform for the President's inaugural event. Greenwood performed his iconic "God Bless The USA" with the United States Marine Corps Band just prior to Donald Trump's swearing in; Carrie, after some production issues delayed her performance, invited the crowd to help her sing "America, The Beautiful" a cappella, earning her a warm reception from those gathered and those watching at home, who took to the Internet with comments like, "Carrie Underwood mouths 'I’ll just sing' after the music fails to play to accompany her. Absolutely gracious, poised, talented lady." See Carrie's performance below