Vermont banjo picker Gordon Stone and Nicaraguan guitarist Remigio Hodgson have never played together in person. But you might not guess that listening to their “virtual” jam session.

The musical pairing comes at the end of Winooski photographer Dan Higgins’ new documentary, Burlington & Puerto Cabezas: Sister Cities for 25 Years. On a split screen, Hodgson strums and sings a song called “Autonomy” outside a wood-sided jungle hut, while back in Burlington, a headphone-wearing Stone plucks along.

The virtual duet conveys the arc of Higgins’ homespun film: how Burlington’s sister-city relationship with Puerto Cabezas, Nicaragua, has evolved. Originally a political and humanitarian response to Reagan administration meddling in Central America, it’s become a cross-cultural exchange that’s produced some unlikely artistic collaborations.

To commemorate its 25th anniversary, Higgins has distilled more than 100 video recordings and a mountain of photographs into a 54-minute montage that traces the quarter-century history of the sister-city program.

When Burlington adopted Puerto Cabezas, called Bilwi by the locals, it was an act of defiance against President Reagan’s actions fueling the bloody civil war in Nicaragua.

Grainy film footage recalls the sister-city movement’s birth: Vermont activists march down Church Street. A darker-haired Bernie Sanders, then mayor of Burlington, speaks out in City Hall Park against the “war and destruction” in Nicaragua. And the most dramatic act: Burlingtonians pack 500 tons of humanitarian aid into cargo containers bound for Puerto Cabezas, an indigenous town of 20,000 on Nicaragua’s isolated Atlantic coast.

“Residents of Burlington like to have their own foreign policy,” says Higgins, a retired University of Vermont art professor. “Burlington residents always think that when there’s trouble in the world, they should get involved.”

Burlington made another hefty gift to Puerto Cabezas in 2005, when $11,000 was raised to help repair the town after Hurricane Felix ripped through with 160 mph winds. Queen City residents also helped establish a tree nursery project to replenish a landscape badly deforested by American logging companies in the early 20th century.

Yet the real riches haven’t come in direct aid, Higgins suggests, but in cultural exchanges that helped the residents of each town better understand the other.

Higgins shows Wolfsong, an Abenaki storyteller from Vermont, swapping North American tales with the Miskito, Mayagna and Rama Indians who make up most of Puerto Cabezas’ population. Wolfsong brings the group small packs of maple sugar that melt into syrupy goo in the jungle’s sweltering heat.

In another scene, volunteers from Johnson State College give the local hospital a new coat of paint. Stonemason Charlie Delaney is depicted helping young men build a cinderblock and wood addition to a dwelling. And we see Nicaraguan Howard Jaentschke in Higgins’ Winooski kitchen, whipping up ethnic recipes for a cooking show that aired on Burlington public access TV in the 1980s.

Several Vermonters instrumental in launching and sustaining the sister-city program are interviewed in depth, among them Marvin Fishman, Robin Lloyd, former Burlington Mayor Peter Clavelle, Mary Brook, Charlie Delaney and Higgins himself.

“I wanted to show the richness of this 25-year history and the variety of ways people of Nicaragua and Vermont have used the sister-city umbrella,” says Higgins.

The photographer-filmmaker has traveled to Puerto Cabezas yearly since 2000, teaching locals to use video cameras to document their own lives. On his next trip down, in February, Higgins is bringing Gordon Stone’s new CD.

“I want to see what kind of choreography the local dancers would come up with for Gordon’s music,” Higgins says.