Well, everyone. I hope I can share some information from the Marine Corps and Navy Bands Ceremonies Handbook to shed some light on proper protocol. Our first concern in this thread was :
1. "A Crowd removed their hats, some put their hands over their hearts. I am sure many of those folks did even know the difference between America the Beautiful and the National Anthem. But I also noticed that players and staff on the field faced the flag, stood at attention and removed their hats. I do not believe that is necessary. I think simply standing at attention and facing the flag is more then enough. What say you? Please provide references when possible."
ANSWER
According to Marine Corps Drills and Ceremonial Manual, "When special circumstances, such as use of a gymnasium, hangar, and hangar bays dictate, the commanding officer may direct that participants and guests alike remain covered and render appropriate salutes as required by the particular ceremony.In such instances, commanding officers will detail the specific requirements for remaining covered and rendering appropriated salutes.
THEREFORE, the person in charge of the ceremony shall, prior to the playing of "America the Beautiful", the explain to the audience to please remain standing, covered members to stand fast (no salute) and civilians to place their hand over their heart. It is rather important the players and staff "face" the flag to render the only honor they can while remaining covered. If players choose, they too may place their hand over their heart. This is all said "PRIOR" to playing "America the Beautiful." Everyone present will listen to the instructions by the emcee and do what they are asked. Especially if someone here has decided to show the National Ensign respect.