Country star Carrie Underwood gave an impromptu a cappella performance of 'America the Beautiful' at Donald Trump's second inauguration on Monday after a glitch left her without backing music.

Country superstar Carrie Underwood performed “America the Beautiful” at the inauguration of President Donald Trump on Monday, but not the way she expected she’d sing it. Underwood had to improvise and sing acapella at the last moment when there was a technical problem with the band or music that was supposed to accompany her performance.

Besides Carrie, opera singer Christopher Macchio performed “O America,” and the national anthem, during the inauguration. Country singer Lee Greenwood also performed “God Bless the U.S.A,” prior to Trump taking his oath of office.