my kids know it, too. :-)
And Austin sings the national anthem ALL THE TIME! And he tries to sing it with vibrato.... he heard me practicing for a change of command a couple of years ago, so now he thinks he needs to sing it like a woman.
Also... I have taught my children that it is disrepectful to the National Anthem to clap afterwards. The clapping started when it started being sung at baseball games and people started clapping because the game was starting. Before long, people clapped after the National Anthem everywhere. You are NOT supposed to clap after the Nat'l Anthem! (ok, stepping down)