Angie and Rohan Robinson wanted to do something different for their wedding. So Saturday, on the crest of a hill overlooking the Petaluma River in an outdoor chapel with hay bales for pews and the mid-day sun breaking through the clouds, the couple tied the knot at the Rivertown Revival festival.

"We've been engaged for three years, so we wanted to do something non-traditional, and we wanted to get dressed up in costumes," said Angie Robinson, 28, of Santa Rosa, just before the newlyweds set out on a celebratory boat ride under a parasol. "It was perfect."

Her husband concurred. "Great energy, a lot happening, and everyone's on the same vibe," said Rohan Robinson, 29, also of Santa Rosa.

The second annual Rivertown Revival at the Petaluma Heritage Center delighted thousands of locals on Saturday, many dressed in historic costumes evocative of bawdier times.

Down the hill a bit, a tap-dancing Lisa Pesch, who goes by the stage name "Artemis," entertained passersby, sang and also played the cello with the band "Conception Vessel One."

Others broke out flutes or washboards in spontaneous old-timey jams as children licked ice cream cones while perched on piles of hay.

By noon, about 1,600 people had arrived, and the crowd was growing.

Emmy, 31, of Petaluma, who adopted the last name "Von Trapp" for the day, dressed up in a frilly pin-striped blouse that she'd made, a tight bodice and a black skirt puffed from underneath by multi-colored crinolines.

"I normally dress like this," she said. "We live in a very casual society where people wear sweatpants everywhere. I like it when people want to dress up and get a little dapper."

On the water, boaters steered hand-crafted vessels, some of them foot-powered, in a slow but spirited "drag races." A group from the Unitarian Universalist Church in Petaluma gently rowed a wooden boat arched with rainbows. One vessel that resembled a cross between a water mill and a hamster wheel was powered by daring souls walking inside the wheels on either side.

An eleven-foot-tall swan adorned with a necklace of flowers gracefully floated down the river holding boat builders Shawn McCaffery, 36, and Ron Keeley, 56, both mechanical engineers and Healdsburg residents.

"We built the swan to be the crown jewel of the parade," Keeley said.