- President-elect Donald Trump's inauguration festivities kicked off Thursday night with a 'Make America Great Again!' welcome concert
- Lee Greenwood, Tim Rushlow and The Piano Guys said they're not apologetic for performing
- Jackie Evancho, who is set to perform the National Anthem on Friday, called the backlash 'sad'
(CNN)Artists who are taking part in President-elect Donald Trump's inauguration festivities are not apologetic.