It started with a photograph.

It was a faded photograph of a very serious-looking group of young men in suits and ties, holding musical instruments. Avner Yonai immediately recognized his maternal grandfather and two granduncles among the musicians, and a plan took seed in his mind.

It is a long way from the Polish town of Gora Kalwaria, known as Ger in Yiddish, to the stage of the Skirball Centre at NYU, but Yonai’s idea has made the trip as the Ger Mandolin Orchestra. An ensemble of 11 of the best mandolinists in the world, they are a living, breathing — and swinging — memorial to Yonai’s family and an all-but-forgotten musical tradition. And the group is one of the musical highlights of next week’s sprawling and eclectic Kulturfest event.

Yonai, an Israeli-American businessman based in the Bay Area, saw the photo in the Yizkor book of Ger when visiting with family members in 2009. His grandfather had been a staunch Zionist and made aliyah in 1935, but the rest of his family was among the 3,500 Jews, half the town’s population, who were killed when the Nazis seized the town.

“My grandfather passed away in 1996,” Yonai says. “He never talked about life in Poland. When I saw the movie [based on Jonathan Safran Foer’s novel] ‘Everything Is Illuminated’ in 2007, I really connected with it, with the idea of going back to Europe to explore my family’s history. When the hero visits the site of a shtetl in Ukraine in the film, there’s a monument to the Jews who were murdered on March 18, 1942; I was born on March 18, 1971, so I took it for a sign. Two weeks later I went to Poland — no preparation, no research, I only knew the name of the town.”

The result was a warm and burgeoning relationship between Yonai’s family and the current residents of Gora Kalwaria, and a stone monument to the town’s victims of the Shoah. Yonai wasn’t satisfied. He wanted a living monument, but until he saw the photo he didn’t know what form it would take.

Now he knew and when he flew back to San Francisco, he contacted Mike Marshall, one of the world’s great string players, who has worked with an amazing range of musicians, including David Grisman, Bela Fleck, Edgar Meyer, Chris Thile, Joshua Bell, Darol Anger, Hamilton de Holanda, Hermeto Pascoal, Mark O’Connor and Stephane Grappelli.

“Marshall liked the idea and he knows a lot of musicians,” Yonai says with characteristic understatement.

Essentially, Marshall just spun his Rolodex and plucked a who’s who of mandolin players.

One of the musicians he called was Eric Stein, director of the Ashkenazi Foundation in Toronto, and founder and leader of the klezmer group Beyond the Pale.

“He said to me, ‘We’re putting together this interesting little ensemble and you were recommended to me, I understand that you do a lot of arranging work with Jewish music,’” Stein recalls. “Mike has been a huge influence on me. He was coming into the project without much experience in Jewish music and klezmer, but he brought together great musicians who could adapt to new material.”

But what material? As both Yonai and Stein note, there was no documentation of the repertoire of the original Ger ensemble.

“There are hundreds of photos as historical evidence of mandolin orchestras,” Stein says, “That was a context for amateurs to make music. They tended to be community groups with a mixture of professional and non-professional musicians. So there was less rigidity in terms of choices of repertoire.”

Jeff Warschauer, another member of the group, explains, “The mandolin orchestras here and in Europe [in the early 20th century] are a clear case of the flowering of secular Jewish culture, particularly in groups like the Workmen’s Circle, and organizations centered around unions. The secular organizations took the place of going to shul. The mandolin orchestras here played Italian music, classical, Jewish stuff.”

The make-up of the Ger Mandolin Orchestra reflects that eclecticism. Simply put, it’s a gathering of virtuosos of an under-appreciated instrument.

And it’s better than just a photograph.

The Ger Mandolin Ensemble will be performing Thursday, June 18, at the Skirball Centre, NYU (566 LaGuardia Pl.) at 8 p.m.