Heads turned in bars and restaurants in the West Village on Saturday night. On the High Line, people held camera phones. Taxi drivers honked and rolled down their windows to whistle. Workers closing the Magnolia Bakery on Bleecker Street for the night opened the door to cheer. In the narrow doorway of a silversmith’s shop in Greenwich Village, a woman started gyrating.  “What’s going on?” passers-by asked one another. “A flash mob?”  “Where’s the music?” a woman asked.  “This tryouts for ‘Glee’?” one man wondered aloud.  “It’s a global floating dance party,” called out one of the 90 or so shimmying, bopping and skipping dancers, who were winding their way from Chelsea Piers to the High Line and through Greenwich Village. Explanation offered, the man plugged his iPhone earbuds back in and sprinted to catch up with the crowd.  Brought together by Facebook and word of mouth, the mass of dancers were all silently moving to the beat of the same D.J. track, which they had downloaded before meeting at a park north of Chelsea Piers. Throwing their arms up and swaying at the hips, they swung themselves around poles, clambered onto outdoor furniture, and rippled down the streets of Chelsea and Greenwich Village. Much the same thing had happened in a dozen cities around the world starting the night before, with each dance party picking up at 10 p.m. where the previous one had left off.  “This is so ridiculous, but so awesome!” one young woman yelled to a friend as the group left the grassy bowl where they had started and sprinted for some patio furniture. Some jumped on the tables; others jumped onto each other’s shoulders. A few stragglers were content to dance a few yards behind the rest of the group, closing their eyes and twirling in place.  “More energy, c’mon!” a young man shouted. “More vigorous move choices!”  “Are you on the right beat?” one dancer yelled to another.  The event was the brainchild of Tully McLoughlin, a Yale graduate living in Ghana. Mr. McLoughlin and his dance-party partner, Alf Molinas, a friend from college living in Tokyo, say they envisioned the event as an experiment in social media and mobile technology: Getting hundreds of people around the world to use Twitter, Facebook and cellphones to create a global flash mob.  But all of that was lost on many of the passers-by who stopped to watch the dance party.  At the High Line, a couple stopped several yards short of the stairway to watch the group run up the stairs. The couple linked arms as they paused, the man smoking, the woman smiling.  “Let’s join in!” said one young woman on the High Line before pulling her friend into the mass of dancers stomping on a long bench.  When the party reached Abingdon Square Park, one man left his friends to run over and ask what was going on.  “That is so sick! Can I listen?” he said, plugging one iPod earbud into his right ear. “Hey, I can dance with you guys!”  At the intersection of West Fourth and Cornelia Streets, where the mash-up switched songs to Duck Sauce’s “Barbra Streisand,” three women listened with interest to a dancer’s explanation of what was going on.  “High five,” one of them said, high-fiving the dancer. “If only I had a download. Keep dancing!”  “It’s just a flash mob,” one said, dismissively.  “They look like fools,” another said.  For the most part, the several New York City police officers the party ran by merely shrugged at the dancers’ antics. Two officers by the Hudson River were too absorbed in their cruiser, which had broken down by the West Side Highway, to notice. A couple of security officers did intervene, attempting to shoo the group away from the Hudson River Greenway, where the group had picked up another 20 dancers.  “You have to have a permit if it’s a group of 20 or more,” one of the officers announced, “especially if I can hear you all the way down there from here.”  “This is a global floating dance party,” Alex Kramer, one of the group’s local organizers, said earnestly. “It’s going on all over the world.”  “You need a permit to do anything,” the officer repeated.  In the nighttime heat, most of the dancers’ shirts showed large sweat stains by the time they reached Union Square, the group’s last stop. The light rain that began to fall drew a cheer. The group hurried into the subway station, paused for a few minutes of dancing, then hurried out again. Under the gaze of the equestrian statue facing a Whole Foods market, the dancers huddled, raised their hands in the air, gave a cheer and — walking now — headed for the nearest cold drink.
On Saturday night, a global dance party brought together largely by social media mystified and enthralled passers-by in Lower Manhattan.