On Friday evening at Built on Stilts, Carol Loud participated in what she said would probably be her final performance at the annual festival. Ms. Loud, 85, wore a dress she received six decades ago. It was red, velvet and floor length. She had a flower in her hair. She carried a single chair onto the stage and improvised around it, twirling across the entire floor, while pianist Lisa Rohn played one of Chopin’s nocturnes.

“I love Chopin and I love this dress,” Ms. Loud said after the final curtain call. “It was made by a friend in the neighborhood. I wore it when I was 22 or 23 years old.”

She said each time she performed the dance at rehearsal and in the festival was different. The first time was full of angst and the desire to keep dancing. Friday, she drew laughter with coquettish glances and tiny shimmies.

Maeve Cook Martin and Pickle Eville. — Jeanna Shepard

“Tonight had to do with flirting with Chopin,” Ms. Loud said.

Hundreds gathered at Union Chapel for the first nights of the free, all-ages performance festival that has returned to the Vineyard every August for 23 years. As always, each evening began with an improvised drum circle. One night, a little barefoot girl with a scrunchie around her wrist stood in the center of the circle of adults, patting a small drum energetically. Dancers gathered around the perimeter of the stage, stretching and swinging their arms before the unpredictable show officially began.

Each act was a surprise.

On Friday, Esther Richmond’s MV Line Dancing Polar Bears, a group of 10 women with glittering hats and sequined costumes, danced to Stevie Wonder’s Isn’t She Lovely to a lengthy applause. They were immediately followed by a Tessa Permar, who wore face paint and a lab coat and moved creepily to Billie Eilish’s haunting chart topper Bad Guy.

On Sunday, Maggie Sabella danced to audio recordings from Senator John McCain’s funeral. Ted Box, Scott Crawford,and Wayne Elliot performed a partially improvised dance as Bruce MacNelly played the electric guitar. A group of five women danced a mambo with inflatable pool tubes as their partners.

Abby Bender, Grace Hall, Laura Hall and Lucia Dillon. — Jeanna Shepard

The Sunday crowd was wild for Zora Morais, Madison Pitman and Nala Pitman’s hip hop dance called Best Friends. The three girls wearing matching pink sneakers were mobbed by family and admirers after the show.

“My heart kept on, like, dropping,” Nala said of her nerves.

Mother and daughter Stephanie Lawson-Muhammad and Jordan Muhammad created their piece What Goes Around in just two weeks

“We rehearsed in our house, at the East Chop Lighthouse, in our yard,” Stephanie said. “There was a lot of grass dancing.”

Jordan, 17, performed her own choreography for the first time at Built on Stilts last year. Inspired by that performance, her mother Stephanie started taking weekly dance lessons to celebrate her upcoming 50th birthday. In this year’s dance, choreographed to Oasis’s Wonderwall, the two literally leaned on one another.

“We could hear the meaning of a mother daughter relationship in the song,” Jordan said.

Remaining performances for Built on Stilts are August 15, 17 and 18. All shows take place at Union Chapel in Oak Bluffs. Doors open at 7:30 p.m., and the show begins with a drum circle. Dancing begins at 8 p.m.