Since the 19th century there's been a tradition of classical music audiences maintaining silence during performances. Throughout the 20th century, any noise -- be it conversation, coughing, rustling programs, unwrapping candy or even applauding between movements -- was considered inappropriate.

Times seem to be changing, and not everyone's happy about it. During the St. Paul Chamber Orchestra season opener, Mozart's "Don Giovanni," the audience was enthusiastic -- perhaps overenthusiastic. More than once, conductor Roberto Abbado glared as delicate codas to arias were drowned by applause.

"I saw that look," said principal bassoon Charles Ullery of Abbado's displeasure.

"The applause threw a hitch into what he was trying to do," said concertmaster Steven Copes. Eventually, Abbado opted to gesture when it was appropriate to applaud.

Minnesota Orchestra artistic director Osmo Vänskä takes a more relaxed view. "It's not ideal, but I don't feel it is an intrusion. I stay calm, because applause is always a positive signal, even if the timing is not perfect."

"I'm not sure the old tradition has much validity," Copes said. "Personally, I don't have any problem with a lot of applause. I've gotten used to it."

"If people want a hermetically sealed, uninterrupted performance, they can put a CD in their home entertainment center," said SPCO President Sarah Lutman. "A concert is interactive."

But some find this new informality disruptive. Veteran concertgoer Roger Burg said, "It breaks the silence that I need to let the music rest before we move on. I love the stillness. There is something about being in a room full of still people."

Marty Rossmann, who has been attending SPCO concerts for decades, agreed. "In the moment, it does bother me. But I get over it and the music goes on."

She admitted she found herself applauding inappropriately during Joshua Bell's appearance with the orchestra this spring. "It was partly his exuberance," she said. "My husband poked me to stop."

That kind of spontaneity excites Lutman. "If audiences are responding in an authentic and enthusiastic way, that's tremendous."

Burg suggested that a directive in the program about proper etiquette might be helpful. But Ullery worried, "If there are too many rules, it might feel too much like church."

This unrestrained attitude makes Black want to return. "I thought I might be intimidated. I expected it to be formal, but there was less of that."

Even other peripheral noises, like coughing, don't raise as many hackles as might be expected. "People cough sometimes. That's part of the performance," Copes said. "People in the orchestra cough sometimes."

This may signal the evolution of a new tradition.

William Randall Beard writes regularly about music and theater.