They came. They bobbed - some awkwardly. They sang. "Never gonna give you up. Never gonna let you down. Never gonna run around and desert you."
Then after three minutes and three seconds, the young fans of 1980s British pop star Rick Astley dispersed.
Yesterday, about 50 people - some dressed in 1980s garb such as torn sweat shirts, bright high-tops and oversized plastic sunglasses - swarmed to a bridge at the Inner Harbor to "rickroll" Baltimore.
Rickrolling is an Internet prank in which users click on a supposedly serious link that instead takes them to a music video of Astley performing his 1987 bubble-gum pop song "Never Gonna Give You Up."
About 50 Astley devotees belted out the catchy lyrics. Tourists and onlookers stared, some pulled out their cameras, and others shrugged and joined in the singing.
After the song ended, participants dispersed immediately as if nothing had happened. The gathering was what is known as a "flash mob" - a brief public spectacle loosely organized over the Internet or by word of mouth.
Flash mobs in cities such as New York and Toronto have gathered to freeze in place at a train station, break into dance or have a huge pillow fight for a few minutes. Then the participants scatter.
Last month, about 300 people invaded a London train station for a live rickroll, singing along to Astley's song. That event inspired 23-year-old Baltimore resident Ryan Goff to organize what he believes is the first American rickroll.
"I'm in love with this song," Goff said. "I thought I'd be absolutely sick of it, but I like it more. I'm working on singing it backward."
Rickrolling has become a popular prank, used by YouTube to trick Web surfers on April Fool's Day. Users who clicked on the site's "featured videos" were instead taken to the Astley music video.
The video features a baby-faced Astley, wearing high-waisted jeans and a denim shirt, swaying side to side. He declares his unending devotion while two women dance and spin next to him. The video also pans to a bartender who twirls and cartwheels over a countertop.
Goff has targeted his friends and family for rickrolling - even his grandmother.
"I told her to check out the video of my little brother's piano recital, but it was a rickroll video on YouTube," Goff said. "So I rickrolled my grandma, but she's kind of into it now; she's singing along."
A few minutes before 1 p.m., a group of people in their 20s sat on the steps of the Barnes & Noble Booksellers store facing a bridge that connects it with the National Aquarium. Others shuffled around the bridge, glancing at their cell phones to check the time.
Goff, dressed in a trench coat, walked to the middle of the bridge. The boombox he had planned to bring wasn't working, so he brought an iPod, speaker and bullhorn. Once he pulled the items from his backpack, people cheered, ran onto the bridge and flocked around him.
But the speaker malfunctioned, so the crowd ended up singing a cappella. Crooning the song through the bullhorn, Goff pumped his fist in the air as the crowd danced and clapped around him.
"It's grass roots; you've got to make the best of it," Goff said after the event. "It's all in the spirit of Rick."
Yesterday's flash mob was expected to have 327 participants, according to a guest list on the social networking Web site Facebook, but about 50 showed.
"I guess not everyone is dedicated to rickrolling as we are," said Frank Short, 20, who drove from Fairfax, Va., to be part of the flash mob. "I would've flown here. I'm infected by this song every day."
When asked whether he was getting tired of "Never Gonna Give You Up," Short replied, "I don't think that's possible. I'm offended by the question."
Goff advertised the event on Facebook, Craigslist and some Baltimore message boards. The word-of-mouth marketer from Fells Point invited his friends and urged them to tell their friends.
"The turnout was decent," he said. "I would've been happy had 10 people shown up."