I watched a video where someone sings the Star Spangled Banner as a guy paints the Statue of Liberty and I noticed no one else appeared to be singing. And now I've noticed it more and more.
Nearly everywhere I've been, everyone joins together to sing the national anthem. There may be someone leading it on microphone but it's expected that everyone sing. It seems in the US one person performing it and everyone standing around with their hand on their heart. Is it just my confirmation bias? Is it out of respect for the performer? There seems to be much more flexibility in how the anthem is performed in America, so is that why people don't join in? It seems like a difficult song to sing, is that why?