My own memories of 9/11 are (blessedly, considering what’s come later) self-contained. Working a full day at the coffeehouse, not wanting/wanting to be there, spending a few hours at home glued to the TV, then going to a Laurie Anderson concert.
No one was sure whether she would cancel the show or not, but she didn’t, and it remains probably the most meaningful concert of my life. During the beginning of her first song she said, simply, “We’d like to dedicate this show to all those who died today.” And that’s the only thing she did differently. Quite a lot of her songs were/are about NYC, so merely performing them as written said everything that needed to be said that evening.