Last year, there were 32 of them. They came with their instruments from across the globe to make music together and to invite audiences in cities along the East Coast of the United States to join this grand exercise in cultural diplomacy.

It went well. And now the program’s sponsor, the U.S. State Department, and producer, Found Sound Nation (the social engagement arm of the new music group Bang on a Can), are at it again, using up the rest of a two-year grant worth $1.25 million.

The cultural exchange initiative is called OneBeat. Its organizers call it a unique “musical journey.” Its website describes it this way:

“It is a chance for adventurous musicians from an incredible diversity of traditions to seek common ground, create new musical combinations, push the boundaries of music technology, and find ways to involve all members of society in the process of musical creativity. ”

This year, 25 musicians are involved, according to Found Sound Nation’s Chris Marianetti.

“We didn’t have any idea when we started how many applications, how many people we’d get,” Marianetti said. A few hundred applied last year. “This year, we had around 1,500 applicants.”

They used an online platform to submit audio files, videos and essays. Then program directors Marianetti, Elena Moon Park and Jeremy Thal spent nearly four months reviewing submissions, soliciting input from embassy personnel and musical colleagues.

The program begins with a two-week workshop at Atlantic Center for the Arts in New Smyrna Beach, Fla., that encourages interaction and experimentation. Then the group hits the road: Charleston is the first stop.

In each city, OneBeat musicians team up with local artists for collaborative learning and performances. Here, they will work with musician Bill Carson, educators Junius and Tracy Wright, Kim Larson of Girls Rock/Hungry Monk and others.

Additionally, three collaborators with a national profile are joining the effort this year, working with the fellows during their Florida residency: Mark Stewart, a guitarist and instrument maker who has played with Paul Simon; percussionist Jamie Haddad; and singer Helga Davis, who has worked with Robert Wilson and Philip Glass, among others.

The fellows form ensembles, large and small, to try different instrumental combinations and mix styles and rhythms, Marianetti explained.

“Thinking beyond nationality is interesting, beyond what we perceive of as another culture,” he said. “There is so much cross-pollination now with how music moves, so people bring what they feel are their traditions, but often (discover that others share) similar melodies or rhythms.”

Among the international fellows are a Russian beat boxer, a South Korean woman who plays traditional instruments, a Cambodian percussionist-vocalist, an American violinist and a Venezuelan maraca player.

“It’s quite the diverse and eclectic bunch,” Marianetti said.

The OneBeat crew will offer two public concerts while in Charleston, one on Sept. 24 at the Pour House, 1977 Maybank Highway, featuring collaborations with local musicians and special guests.

Sets begin at 7 p.m. on the outdoor patio stage and continue on the main stage ($5 cover).

Another concert (free) is planned for 8 p.m. Sept. 25 at Circular Congregational Church, 150 Meeting St.

Additionally, the fellows and their engineers hope to set up a street studio in Marion Square, enabling passers-by to participate in the music-making process, providing samples that can be used to make impromptu recordings.

The idea, Marianetti said, reinforces the notion of cultural diplomacy and community engagement.

“I think it’s such a cool concept,” said Scott Watson, director of the city’s Office of Cultural Affairs. “This is more than an opportunity to check out some music-making in town; it’s a chance to lay down some tracks and join the effort directly, he said. “They’re looking to capture the pulse and the rhythm of the city. ... Charleston is extremely fortunate to be on the itinerary. This is a gift, and not every community gets to enjoy access.”

Malabika Brahma, a 32-year-old singer from Calcutta, India, and OneBeat fellow, said the experience so far has been enriching.

“OneBeat is like the most important thing that’s happened in my life,” she said, excitement evident in her voice.

She is experimenting with new instruments, including unorthodox ones such as door keys and the back of a harmonium, she said.

She is eager to collaborate with all of the other musicians in the group and currently is writing a song that employs the beat boxer from Russia, Master Mike, an Israeli flutist and the South Korean player adept at traditional instruments.

“I’m learning every second,” Brahma said, quickly, in her Indian accent. “This is the first time I’m traveling alone, anywhere. I am so very scared. ... When I came here, I am like a reborn person. I came with no inhibitions. I keep my brain very open.”

Marianetti said OneBeat is about much more than music-making.