To Sing or Not to Sing--?

The recent spate of National Anthem news has confused me. When I hear it, should I salute, put hand over heart, sing along, bow, quit my job, take a knee, go get a beer, or just stand still? We could use a new constitutional amendment that codifies what actions are permissible when dealing with the anthem. Should the president ground Delta airlines or call the parents of the fallen soldiers and apologise for Delta's disrespect to the anthem and the soldiers?

Yes, Trump should call for everybody who disrespects the anthem or the flag to be fired.