At the age of 81, islander Martin Koenig can now see his life’s work and passion before him, encapsulated in a 144-page, large-format hardcover art book with two accompanying music CDs.

The new book, “Sound Portraits From Bulgaria: A Journey Into a Vanished World 1966-1979,” published by Smithsonian Folkways, has been more than 50 years in the making. Koenig will share the book with islanders at a launch party at 4 p.m. Sunday, Dec. 8, at Open Space & Community. The afternoon will include a presentation of films and photographs that are featured in the book by Koenig.

On a recent rainy afternoon, Koenig welcomed a visitor to his Vashon home and thumbed through the handsome and heavy tome, filled with scholarly essays and Koenig’s striking photographs depicting the ancient but vibrant folk music traditions of Bulgarian villagers.

A bespectacled man who looks younger than his years and still speaks with more than a trace of his native New York accent, Koenig marveled at his good fortune in being able to hold such a book in his hands.

He was grateful, he said, that the publisher had shown “tremendous generosity and tremendous trust” in allowing him to have creative control in all aspects of the book.

“Sound Portraits From Bulgaria” has already been celebrated around the world, in vaulted settings.

It launched in September with an accompanying exhibition of Koenig’s photographs at the Bulgarian National Art Gallery, in Sofia — a whirlwind of recognition that included a private audience for Koenig with the president of Bulgaria, Roumen Radev, who awarded him a presidential medal for his 50 years of work championing Bulgarian traditional music and dance.

At the launch of an exhibition of his work and launch of his new book, Martin Koenig received the honorary medal of the president of the Republic of Bulgaria, Roumen Radev (Martin Koenig Photo).

These honors were followed by events at the New York Public Library for the Performing Arts at Lincoln Center, the Hristo Botev School and Hristo Botev Academy in New York City and Washington, D.C., respectively, and the Princeton Public Library in New Jersey.

And as the book launch rolls out, more events are planned for 2020, at such venues as the Northwest Folklife Festival and the Thessaloniki PhotoBiennale, in Greece, as well as presentations in San Diego, Los Angeles and the Bay Area.

But it all started long ago and far away, in a place that Koenig describes as now being “completely gone.”

In 1966, as a 27-year-old, Koenig made his first trip to Bulgaria, armed with letters of recommendation from anthropologist Margaret Mead and folklorist Alan Lomax, determined to study the folk dances of rural communities throughout the country.

Koenig described himself in those days as “a young enthusiast who was smitten by this music and dance form,” who at the time worked teaching Balkan folk dance at Barnard College and Sarah Lawrence College.

“The dancing was so vital and the music was so intense, it spoke to me in a very deep way,” he said. “It hooked me.”

As he traveled, absorbing the culture and speaking with the people he encountered, Koenig became even more captivated by the authentic and old, yet very much alive, music he heard all around him.

The hypnotic sounds of the Bulgarian bagpipe, ecstatic and drone-centric singing, and odd-metered rapid-fire dances he observed painted a vivid picture of a multi-faceted culture that sat at the crossroads of Europe and the Middle East, he said.

Toting heavy audio equipment and cameras, he captured as much music as he could and took photographs not only of the singers and dancers but also those going about their daily lives in villages throughout the country.

He returned more than a half dozen times until 1979, documenting this traditional culture, providing a vivid, first-hand account of joyous rituals, celebrations and festivals.

Almost immediately, Koenig’s work was seen as revelatory.

One of his recordings, made in a rural classroom in 1968, is the haunting folk tune “Izlel e Delyu,” as sung by Valya Balkanska. In 1977, this recording was chosen by Carl Sagan to be included on the famed Golden Record that sits inside the Voyager spacecraft, currently hurdling at 40,000 miles per hour outside our solar system.

Koenig’s visits to Bulgaria took place at the beginning of his lifelong work as a supporter of community-based traditional arts and an authority on European ethnic dance traditions. During the course of his career, Koenig co-founded the Balkan Arts Center, now named the Center for Traditional Music and Dance, in New York, and also conducted field research under the aegis of the Smithsonian Institution and other institutions. On Vashon, he is known for bringing acclaimed Balkan musicians to local audiences and teaching islanders the fancy footwork of the folk dances he has long studied.

Looking back on the pivotal years when he first visited Bulgaria, Koenig said he found a “society that had stood still there for many years.”

“I thought I had fresh eyes being a foreigner,” he explained, “and I took photographs that other photographers didn’t take because they thought it would be there forever.”

Koenig, as an outsider, sensed otherwise. He said he soon realized, even as he documented the agrarian lifestyle and culture, that he was in the midst of a society in rapid transition.

Time has proved Koenig right.

According to the United Nations, Bulgaria today is actually the world’s fastest shrinking nation. Its population — almost 9 million at the end of the 1980s— has now shrunk to approximately 7 million people and is expected to dwindle to less than 6 million by 2050.

The country’s population implosion — and the exodus of Bulgarians from the countryside to cities — posed one of the biggest obstacles to publishing “Sound Portraits from Bulgaria,” Koenig said.

To publish the book, the Smithsonian required that he embark on the impossible task of returning to Bulgaria to seek authorization from the artists or heirs of the many people he had recorded playing music in the 1960s and 70s.

Koenig said he was saved, in the end, by two Bulgarians he had met in the course of his work and had maintained contact with over the years.

One was Gena Traykova, a filmmaker who is currently the head of news at Bulgarian TV; the other was Ivaylo Gogov, a young man Koenig had helped when he visited the U.S. years ago. Leaning on the skills of these two old friends, Koenig located 69 contacts for the 81 people he had recorded, including 11 musicians who were still alive.

Traveling back to Bulgaria to share his photographs and recordings with these people — who saw their dead relatives or themselves as much younger people in the images — was very moving, he said.

But it was also sad, according to Koenig, who said that many of the grandchildren of the people he recorded no longer knew the traditional songs and dances that had flourished for centuries before they were born.

“I went back to the same villages,” he said. “Some had 800 residents [in the 1960s], now there are 80.”

The exodus in Bulgaria and the subsequent loss of cultural traditions reminded Koenig of the world’s current migration crisis.

“They’re not leaving because they want to,” he said. “They leave because they have to.”