If you lived through the early 2000s, the phrase “flash mob” might arouse a vague feeling of dread. The seemingly spontaneous gatherings, often involving some kind of performance, began as a cool-kid phenomenon and devolved with disheartening speed into a corporate marketing tool. By the end of the decade there was a creeping sense, when witnessing a mob or a video of a mob, that something was being sold to you.

Then, several years and several vibe shifts later, came flash Bobs.

Like their older cousins, flash Bobs involve fake-impromptu gatherings in public spaces. But as orchestrated by Bob’s Dance Shop — a group of five performers that its founder Vince Coconato describes as an “immersive dance crew” — the mobs lean silly, colorful and joyfully queer. Featuring routines with disarmingly simple choreography set to wedding-playlist classics, and performed by diverse throngs of mostly untrained dancers, they bring the inclusive spirit of the viral dance challenge out into the fresh air. (And then, in the group’s shared video footage of each event, back online.)

Those strolling the Third Street Promenade in Santa Monica a few Saturdays ago might have wandered into the most recent flash Bob. Eighty colorfully attired mobbers took to the cobblestones, performing a disco-inflected number to a remix of “Le Freak” by Chic. The climax was the reveal of the pop star Paula Abdul, who dance-mingled with the crowd and then hugged everyone within reach.

Abdul, who began her career as a dancer, said in an email that she considers herself a Bob “lifer.” (She befriended the Bobs while waiting in line at the airport.) “I’ve always been a big supporter of dancers and choreography,” she wrote, “but this group embodies more than just movement.”

Over the past few years, Bob’s Dance Shop has built a devoted following around the cathartic power of dance-party energy. “There’s a selflessness to it,” said the dancer Sarah McCreanor, known as Smac, who has participated in two flash Bobs since connecting with the group on Instagram. “Everybody there, whoever they are, has the same agenda, which is to have fun.”

Fun remains a priority. But in recent months Bob’s Dance Shop has also begun positioning its events as acts of protest. Of the five main Bobs — Coconato; the performer Jacob Garcia, known as Lito; the dancer and choreographer Lucas Hive; the musician Kameron With a K; and the dancer and choreographer Malia Baker — all but Baker are queer. (And, no, none are named Bob.)

Flash Bobs have been gaining momentum as conservative politicians across the United States have pursued laws targeting L.G.B.T.Q. rights. Showing up “boldly and queerly in public places,” as a recent video caption read, has become part of the Bob mission.

“We like to call ourselves ‘joy activists,’” Coconato said. “And our activism is about queer joy because that’s really our own story.”

Coconato, 31, grew up “very closeted,” he said, in small-town Florida. His first dance experience was as high school class president, teaching his fellow seniors the “Thriller” choreography for a homecoming pep rally shortly after Michael Jackson’s death. Though he had no dance training, he found he was a natural teacher. At the University of South Florida, he choreographed dances for his fraternity, and staged his first flash mob — this was at the tail end of the trend’s first wave — for 300 students.

After college, Coconato came out to his family and friends, moved to Los Angeles, and took a job at a video postproduction company. One day, he wore a yellow Lion’s Club shirt embroidered with the name “Bob” to work. An unsuspecting client said, “Hi Bob! What’s your story?” Coconato playfully improvised a character that he later realized was inspired by his own metamorphosis: a gay Southern choreographer named Bob.

Coconato had been considering organizing another flash mob, after his college success. “And I had this moment of, ‘Oh, A flash mob named Bob,” he said. “It just rolls off the tongue.” In 2017, he and a few friends put on the first-ever flash Bob, a campy gambol down the same Santa Monica street that served as their most recent stage, with Coconato wearing the yellow Bob shirt.

After losing his day job, Coconato registered the name Bob’s Dance Shop, and in December 2019 he began hosting pop-up dance classes at rented studios, advertising on Instagram and teaching festive choreography to whoever showed up. The classes maintained the tongue-in-cheek spirit, and some of the spontaneous feel, of the flash Bob.

When the pandemic hit, Coconato and a few friends hunkered down in a house in Los Angeles. With in-person classes, let alone flash mobs, an impossibility, Coconato recruited two of his dance-inclined roommates, Lito and Hive, to help him take Bob’s Dance Shop virtual.

They joined the many dance creators then offering free classes on Instagram Live, and began filming lighthearted choreography videos that had “big Bob energy,” Lito said, as well as sleek production values. A few months later, as their online audience grew, they invited Kameron, a friend from the music scene, to become part of their growing crew. (Baker, the newest member, joined this year to help with choreography as the scale of the group’s projects increased.)

In June 2021, as Covid restrictions eased, the Bobs planned a grand IRL celebration. On Father’s Day, they mounted the flash Bob that would seal their fate: 50 dancers performing to “Around the World (La La La)” for a cheering crowd in Ocean View Park. Footage of the event, posted to Instagram and TikTok soon afterward, went super viral.

“I think everyone was just so happy — desperate, really — to be outside and dancing together, or even to see that that was possible again,” Coconato said.

Since then, the Bobs have mobbed locations all over, from Grand Central Terminal in New York to Buckingham Palace in London. They’ve been invited to flash red carpets, and have appeared at the Lollapalooza and Austin City Limits music festivals. Last year they were asked to “seed” flash Bobs for the music duo Sofi Tukker, planting themselves in the audience before being invited onstage. Now they’re touring with the band, and with the DJ and producer Purple Disco Machine.

“They are world-class vibe curators,” Sophie Hawley-Weld and Tucker Halpern, of Sofi Tukker, wrote in an email.

Over time the group has honed its flash Bob formula. Each event begins with a ticketed workshop, essentially a two-hour dance class, during which anyone with adequate enthusiasm can learn a short choreographed routine — and culminates in a mob-style performance for an unsuspecting crowd. Usually the Bobs teach a few basic steps that have become signature “Bobographies,” like the “people’s dance” (touch your far shoulder, touch your near shoulder, raise your hand over your head) and the “flamingo” (touch your index and middle fingers to your thumb, raise your hand over your head).

Though these are not moves from the TikTok dance challenge vernacular, the philosophy is similar. “It’s all about making a dance language that’s learnable and replicable,” Coconato said.

It’s also a language shaped by L.G.B.T.Q. culture. “The way we perform is very much inspired by the queer community and the drag community,” Lito said. Much of the group’s choreography involves elements of voguing, a style created by queer Black and Latino dancers. Lip-syncing, a staple of drag shows, factors into nearly every performance.

With L.G.B.T.Q. rights under attack, the Bobs have begun explicitly framing their performances and videos as activism. Coconato wants to choose future flash Bob locations strategically, he said. There are plans to host one in Tennessee, which recently banned gender-affirming care for transgender youth and restricted drag performances, this June. He also hopes to mob deep-red rural Florida, where he grew up.

“You just want to flood those areas with as much joy as you can,” he said.

Also in need of more joy: the cutthroat commercial dance industry. Bob’s Dance Shop initially existed largely outside of mainstream professional dance, with most of its members, mobbers and fans coming from non-dance backgrounds. Now it’s earning a following among pros seeking a more relaxed, upbeat approach to performance.

Baker, whose credits include dancing on “The Marvelous Mrs. Maisel” and choreographing for “So You Think You Can Dance,” said she had been feeling “dejected and frustrated” by the competitiveness of professional dance before joining the Bobs. Smac, who competed on both “So You Think” and “Dancing With Myself,” described the flash Bob workshops as “stress-free environments, which for professional dancers is basically unheard of.”

Next month, four out of the five Bobs are relocating to New York City from Los Angeles. They hope moving their base to the East Coast will help them forge better connections to the worlds of theater, music and fashion, areas they’d like to explore further. Social media may have been the group’s route to pandemic-era success, but now the focus is on good, in-person vibes.

“Where we’re excited about growing the most,” Coconato said, “is not the social platform, it’s the physical platform — the stage, the runway, the concert.”

Whatever other projects the group might take on, its flash Bobs aren’t going anywhere anytime soon. Or, rather, they’re going many undisclosed places at many undisclosed times.

“That element of joyful surprise,” Coconato said, “is always going to be right at the heart of what we do.”