LONDON - Clapping is now a big thing. Stir-crazy in their locked-down homes, the phenomenon of stepping onto the balcony in the evening, flinging open the windows, to applaud health-care workers fighting the coronavirus on the front lines has gone global.
Part balm, part defiance, part celebration - we're still here! - the practice has migrated, alongside the virus and enforced quarantine, from the Chinese epicenter of Wuhan to the medieval villages of Lombardy, from Milan to Madrid, onto Paris, and now London.
There have been standing ovations, too, in Istanbul, Atlanta, Buenos Aires and Tamil Nadu, India.
In Britain, millions of people came out on Thursday evening to cheer the staff of the country's beloved National Health Service, whose intensive-care units and arrivals and emergency wings are bracing for an explosion in cases, as already exhausted nurses, some wearing garbage bags, are begging for more and better protective equipment.
There were, almost instantly, thousands of tweets with pictures and short video clips of people applauding - from British Prime Minister Boris Johnson to residents of council estates in south London, to Prince George, Princess Charlotte and Prince Louis. Landmarks big and small, from the London Eye to The Shard to local libraries, were lit up in "NHS blue."
"We owe them so much," said James O'Neill, 58, who was clapping from the back garden of his council estate in London's Battersea neighborhood. He is one of the 1.5 million at-risk Britons who aren't supposed to leave their homes for three months. "It must be scary working for a hospital right now. It's scary just walking around," he said.
The phenomenon of people cheering in the evenings began in mid-January in shut-down city of Wuhan in China, where the first social media posts recorded anonymous voices in the night, shouting from their high-rise apartment buildings, a cry of 'jiāyóu! - which literally means "add oil," but translates to "keep up the fight."
The practice took off in Italy, where the shut-ins first emerged to bang on pots, play accordions, wave flags. And, being Italians, they sang. Arias from opera stars. Soccer chants.
In Siena, the people rendered the traditional Tuscan folk song, "Il Canto della Verbena (And While Siena Sleeps)," sung since the Middle Ages. "The back-and-forth choruses echoed down the narrow, deserted street of the medieval town," the Voice of America reported.
By mid-March, the first flash mobs promoted by social media in Italy began to call for group applause for the doctors and nurses risking their lives in the virus wards.
But be warned. In Italy, the applause is being muted, and less regular, as the lockdown has dragged into its third week.
The city of Florence last week put a stop to the ovations out of respect for the dead, in solidarity for people who are suffering and mourning, according to the Corriere della Sera newspaper.
Facing a surging caseload and body count, Spaniards in lockdown are sharing online classes, yoga by Zoom, balcony bingo and Houseparty app get-togethers.
But perhaps the highlight every day is at 8 p.m. sharp, when people lean out their windows to celebrate the "heroes," as they are broadly called, the country's health workers and security forces.
"The applause at 8 p.m. serve as an oasis for those of us who have been indoors for 13 days and counting," said Emanuel Diaz, who lives in the center of Madrid's historic area. "I can honestly say that I look forward to them every single day."
For Diaz and others, the nightly moment gives them a sense of community.
"It's weird to live in a place without actually knowing the people in that place. I was a ghost on my street until I started going to the balcony and establishing relationship with my neighbors," he said. "My neighbor on the front balcony told me last night: 'After this is all over, I can't wait to go to the street to finally meet you and have a drink together.' "
One night this week, police and ambulances joined in the moment flashing their siren lights in front of Madrid's ice skating rink, which is serving as the city morgue.
In Paris, the sound of cheers can be deafening - it resonates down wide boulevards, through thick stone walls and into quiet inner courtyards, where Parisians gather to applaud, even if their apartments do not face the street.
In an editorial on Thursday, the French newspaper Le Monde argued that support for health workers was essential, but that it should extend beyond nightly applause. The real way to support health professionals was to take the confinement rules seriously, Le Monde insisted, as some in France and across Europe have refused to follow their government's lockdown guidelines.
"By respecting and enforcing the rules of containment, by questioning their behavior in terms of the common interest, everyone can indirectly relieve the burden on overworked personnel," the editorial read. "No one should feel exempt from this responsibility.
In Germany, there have been attempts to start a regular evening clap for medical workers, but the clapping hasn't gained the same momentum as in other cities.
Berlin authorities said that last Friday applause broke out "on some streets" in the neighborhoods of Prenzlauer Berg and Kreuzberg for "a few minutes."
"Occasionally cheers could be heard," a news release noted. German hospitals have not yet come under the level of pressure seen elsewhere in Europe. But the emphasis, health authorities say, is on the "not yet."
Residents of cities across Turkey began cheering medical workers last week, in passionate outbursts - accompanied by the flicking of living room lights, car horns and whistles.
"Thank you for your third applause Turkey!" the country's now ubiquitous health minister, Fahrettin Koca, wrote on Twitter Saturday, in a post that included footage of the balcony ritual, which takes place every evening at 9 p.m.
"Let's show our support to our health workers at every opportunity," he wrote.
President Recep Tayyip Erdogan and Emine Erdogan, the first lady, have also joined in, applauding from their balcony in Istanbul.
In London on Thursday, the cheering was raucous. Little streets that have been eerily quiet amid a national lockdown this week, like Rosecroft Avenue by Hampstead Heath, saw neighbors cheering, blasting music from home stereos, waving mobile-phone flashlights and banging on pots and pans.
The applause rippled across central London. "I was clapping and whooping and then laughing," said Susan Schulman, who leaned out her second-story flat in Clerkenwell. "It's a community thing - and it's some sort of communication with people now that you are isolated. It wasn't that long, though - I mean, the Italians do opera. This was kind of whoop-clapping . . .. and you couldn't see any one else. But it did make me laugh."