BEIJING - Along with two dozen of her fellow "dancing grannies," Zhang Jinsu, 60, twirls and steps her way every night across a central Beijing plaza, sometimes gliding over the pavement like a butterfly, at other times marching with a plastic rifle.
But when new Chinese government instructions on such hugely popular - and loud - senior dances take hold, Zhang may need to learn a new routine.
Zhang is part of a senior health trend that's filled squares and apartment courtyards across China, winning the admiration of medical experts but upsetting neighbors over the noise level.
"It's never quiet," said Gan Xuehua, 31, whose apartment in the southern city of Nanchang overlooks a plaza where the women dance. "These grannies play music all day . . . and every night from 7 to 9," he said. "It culminates with 70 to 80 people gathering with two 75-centimeter-tall [21/2-foot] speakers. The music is really loud!"
Last week, Chinese officials stepped into the fray by announcing the imminent arrival of new regulations on where seniors can dance and how loud they can blast their music. They also unveiled 12 officially sanctioned dance steps set to such popular songs as "Little Apple" and "China is Beautiful" - although an official said the steps were not compulsory and merely a suggestion.
To some, the dance clampdown was a step too far for an increasingly restrictive government that has tightened controls on everything from college classroom lectures to the lavish spending of top government officials.
"You're even going to tell us how to dance?" asked Yang Tao on the social media service Weibo.
As a precaution, Zhang said her fellow dancers who gather in front of the Raffles Center in downtown Beijing have already stopped all dances by 9:30 p.m. And to show a government afraid of any sort of organized action, they have started reenacting ultrapatriotic World War II-era skits, to the rhythm of a live band.
"There have been people who have criticized us, but we all came to an understanding and solved the problem," Zhang said. "We do more theatrical dancing, different from the plaza dancing where everyone stands in their own square meter. These new regulations have been discussed for a year now, but we've chosen an appropriate place to dance."
An official at the General Administration of Sport who would only give her surname Yao said the new steps were not mandatory and had been created by experts.
"Apart from those 12 dances, we are also asking people to suggest other dances too," Yao said. "The original goal is to help people exercise in a healthier and more scientific way. We invited health experts to be involved in the choreographing, just to make sure the dances are not too active, because they might not be good for some people with neck problems or heart problems."
She said her department was also working with the Culture Ministry on "specific guidelines on the volume of music" played at the dances and other details.
The enormous popularity of the Chinese square dances, which have been spotted even in Moscow and New York, springs from an urban landscape lacking enough parks and other public spaces that pushes people to gather in front of shopping centers or in playgrounds, said Caroline Chen, an environmental planning expert at the University of California at San Diego who wrote her dissertation on the dances.
Those same factors help explain the ire occasionally sparked among neighbors. A Beijing man did prison time after he fired a rifle into the air and released three dogs on several dancers in 2013.
The dances' popularity also reflects China's rapidly aging society, and meeting the health needs of a growing elderly population will be one of China's biggest challenges, Chen said. "I'm concerned that when there are rules and restrictions put down on how one can dance, that free flow of creativity and spontaneity can be squashed," she said.