Well before the rock band Blues Traveler took the stage Saturday afternoon at the Greenwich Town Party, three fans had already staked out their positions for the show.

Undeterred by a pelting rain, Jeff Toback and his two sons Zach, 7, and Nathan, 6, crouched in their raincoats on the lawn next to the main stage. The boys, like their father, appeared unmoved by the cold, damp conditions, which were more reminiscent of Thanksgiving, not Memorial Day weekend.

"It took a little convincing and motivation this morning, but ultimately you just get up and go," said Jeff Toback. "I saw Blues Traveler when I was in college, and now I get to be here with my sons seeing them play the harmonica again."

Finally, the band announced its presence on stage, as frontman John Popper unleashed a bluesy fusillade on his harmonica. The Tobacks, and scores of others, heartily cheered the opening salvo.

That reception typified the enthusiasm and resilient attitude that prevailed Saturday at the Greenwich Town Party despite the inclement conditions at the waterfront Roger Sherman Baldwin Park. The sold-out event drew about 3,000 during the day and was expected to peak at approximately 4,500 when headliner James Taylor took the stage at 8:30 p.m., according to event manager Scot Weicker.

"It's been a party from the moment the doors opened," Weicker said. "The momentum has been building throughout the afternoon. We couldn't be more pleased with the Greenwich Town Party."

While the rain did not disrupt the schedule, it did claim one casualty: a free "extension" showcase planned for Greenwich Avenue. Unlike the stage equipment at the park, the avenue event's electrical feeds and band apparatus would not have been covered from the rain. Weicker described the cancellation of the extension event as a "heartbreaking decision," but added that Town Party organizers were determined to hold it next year.

Both performers and attendees combated the persistent precipitation with levity and patience.

"We brought out the sun!" Popper exclaimed when the crowd cheered a brief sunburst during his band's set. "We really did that."

The crowds maintained their enthusiasm throughout the day. Even as the temperature dipped below 50 degrees, a throng jumped up and down and clapped robustly for Michael Franti & Spearhead's closer, "Say Hey (I Love You)."

Greenwich natives Caroline Jones and Local Talent also drew strong turnouts for their sets.

Away from the stage, attendees received a welcome as several local establishments compteted in a BBQ grill-off. Bobby Q's claimed the chicken and pulled pork titles. Helmed by Greenwich native Bob LeRose, Bobby Q's operates a takeout establishment at 1340 East Putnam Ave., as well as restaurants in Stamford and Westport.

"Being from Greenwich, it was really important for us to put our best foot forward today," LeRose said. "We're really appreciative to get so much support."

The event also featured a range of fare from other Greenwich businesses, including Aux Délices; Asiana Café; Burgers, Shakes & Fries; Fjord Fisheries; Longford's Own-Made Ice Cream; Méli-Mélo Juice Bar; Organic Planet; Sweet Lisa's Exquisite Cakes and The Ginger Man.

"This burger is amazing," enthused 8-year-old J.T. Spadone about an offering from Burgers, Shakes & Fries. "I hope I can come here every year."

A number of other patrons also said the rain had not tamped down their enthusiasm.

"What rain?" quipped Pete O'Brien.

"We just want to make the most of it," said his wife, Erin.

She added that the outlook of their two daughters, Kelly, 8, and Caitlin, 10, had brightened by enjoying cotton candy before lunch.

Another attendee, Alison Rogers, projected a similarly sanguine attitude.

"It's still a good event, and it's still a good community event," she said. "This is still better than being at home. We have some amazingly generous people in this community who help to make this happen."

Started in 2011, the Greenwich Town Party has grown in its third year into one of the town's premier cultural events, drawing the likes of Taylor, while Paul Simon topped last year's bill. Organizers compare the waterfront showcase to a block party or pot luck dinner. Event donors subsidize about 90 percent of Town Party costs. General admission tickets went for $50, while "Fair Share" tickets, which paid for admission, a donation and a merchandise gift package, sold for $400. The Greenwich Town Party was conceived by Bridgewater Associates founder and Greenwich resident Ray Dalio and inspired by town parties he saw during his travels in Spain.

"This party is for Greenwich residents by Greenwich residents," he told spectators before Taylor took the stage.

Even with rain still pummeling the park during Taylor's set, the crowd maintained its fervor, with the singer-songwriter receiving a resounding round of applause after finishing his first number, "Everyday."

"This is still a great experience," said Scott Moroney, one of those braving the downpour. "I'm a big fan James Taylor fan, and this is special. It's like watching him in your backyard."

pschott@bcnnew.com; 203-625-4439; twitter.com/paulschott