It's okay that Yo-Yo Ma and his fellow musicians instrument-synched their inauguration performance. Their instruments are sensitive. The strings would have broken. Had we actually heard them play that day, according to Yo-Yo Ma, the music would have sounded terrible. No one could have sung along, anyway.
Clearly Pete Seeger and Bruce Springsteen had something different in mind. They invited the nation to sing along.
Pete Seeger has been walking freedom's highway all of his life. Look at him as he runs off of the stage. What an amazing person.