Lisa Grotts is a certified etiquette consultant and a former president of the San Francisco Ballet Auxillary, http://www.amlgroup.com/
In the opera house, symphony hall, and theater, or at a school play, keep these live performance etiquette tips in mind:
Do not arrive late or leave early. It is disruptive to the artists and the audience.
Do not talk during a live performance. All attention on stage, please!
Do not rustle the program or your clothing, and avoid distracting those around you in any way. Watches with alarms and dangling jewelry such as charm bracelets should be left at home. Turn off your cell phone or pager.
No snacking during the performance, please.
Taking your seat: if there is no usher, the man enters the aisle first; if there is an usher, let him lead the way, followed by the woman. The woman enters the row first.
The coveted aisle seat: it is still considered proper for the man to sit ‘aisle-side’ just as he still walks on the curbside when escorting a woman on the street.