Music Center management could help diminish the incidence of coughing during performances by installing vending machines with various brands of cough drops and syrups available. Such medications can help.
The machines could be discreetly located so that their presence would not affect the decor. (I've seen machines vending candy bars prominently displayed in the Eisenhower Theater lobby at the Kennedy Center. Looked tacky!)
A grotesque variant which unbidden comes to mind is the prospect of vendors roaming the aisles just before curtain time, proclaiming, "Get your menthol cough drops, here!!" In keeping with the dignity of the Center, the vendors would be auditioned young singers, cautioned to hawk their wares only in song. In the key of C, of course.