The Charlie Porter Quintet used the power of jazz music abroad to tear down the barriers between people of different cultures.

There was a moment during the Charlie Porter Quintet’s visit to India in May that summed up perfectly what the U.S. State Department’s “The Rhythm Road: American Music Abroad” program is all about. Appearing at a hotel in Hyderabad, the group took a detour from its usual fare of standard and original tunes to play its own interpretation of “Jana Gana Mana,” the Indian national anthem. That’s a risky proposition in any country, given the powerful emotions evoked by a song meant to embody the identity and aspirations of an entire nation. It’s especially so in India, where any deviations in instrumentation, chord structure, melody or length—it should be exactly 52 seconds long—is considered disrespectful by traditionalists.

“It’s hard to describe how powerful that moment was,” says Charlie Porter, the band’s leader and trumpet player, who acknowledges stretching some of those rules in his rendition (listen to an MP3 of their rendition below). “People were crying, and they gave us a standing ovation. Lots of people told us later they had never heard their anthem played so beautifully. That was so rewarding, to know they dug it. That’s the power of jazz music. It’s music of the people – democracy in music – and such a great vehicle when you’re playing abroad because it invites people in. That’s why the rest of the world really `got’ Louis Armstrong.”

Invoking Armstrong’s name was no accident on Porter’s part. His band’s 29-day trip to India, Sri Lanka, Bangladesh and Turkey last spring was a direct descendant of the State Department’s famous “Jazz Ambassadors” tour that sent Armstrong on a three-month sojourn to Africa and Europe in 1956, immortalized in a CBS documentary by Edward R. Murrow. During the height of the Cold War, Armstrong’s magnetic personality and transcendent music created a noticeable thaw in U.S. relations around the world as he met with foreign leaders and drew enormous, adoring crowds wherever he went.

That’s a bit much to expect from a 32-year-old musician from New York who, while greatly respected in jazz circles, is not a household name even in his own country. In fact, none of the bluegrass, gospel, hip-hop, blues, and jazz groups selected for the Rhythm Road program, administered by Jazz at Lincoln Center, are major-selling artists. That’s partly by design; the current program has more modest aspirations than the original, ambitious effort in the ‘50s and ‘60s that sought to refute Soviet propaganda portraying the United States as culturally backward. (Harlem congressman Adam Clayton Powell, Jr. first suggested down-home jazz instead of ballet dancers, who probably couldn’t compete with the Bolshoi anyway). It also reflects a shift in popular-music tastes; today’s American “roots” musicians aren’t nearly as famous as their equivalents were in their day.

But at a time when President Obama has made repairing America’s image abroad a top priority, Porter’s experience shows the small but crucial ways in which music can begin tearing down the barriers between people of different cultures. Begun in 2005, the Rhythm Roads program holds extensive auditions before selecting ten quartets specializing in “quintessentially American” music. These groups then travel to countries not regularly visited by Americans, with the goal of promoting “cross-cultural understanding and exchange among nations worldwide.” By the end of the year, this year’s groups will visit 40 countries, where they’ll perform in public concerts, collaborate with local musicians, hold master classes and jam sessions, give media interviews and – of course – blog about their adventures.

Porter says that during their travels, he and his band – Adam Birnbaum on piano, Scott Ritchie on bass and Jon Wikan on drums – felt an enormous sense of responsibility on many levels: to help keep the neglected art form of jazz alive; to learn about musical styles from around the world that might inform their own playing; and to spread the spirit of inclusiveness that they consider an essential element of both jazz and American democracy.

At every stop, looking for ways to engage audiences, Porter asked about favorite local pop hits or national anthems. “The secret to making jazz accessible is connecting to pop music,” Porter says. He points out that this approach has a long tradition in jazz, from the earliest New Orleans pioneers to ‘40s beboppers who played Broadway show tunes all the way to Herbie Hancock’s recent interpretation of Joni Mitchell songs.

So in Sri Lanka, Porter’s band played the infectious pop hit “Lowe Sama” as well as “Jai Ho,” from the film Slumdog Millionaire. In Bangladesh, they played a beloved Bengali song on what happened to be a day of mourning after a huge fire had swept through the town of Dhaka where they played; the audience sang along in moving tribute to the victims. For the Indian national anthem, the quintet played the 52-second melody twice, and at some concerts even added an improvised section. The song was so tasteful and heartfelt – long, lyrical lines from Porter’s trumpet floating over a thrumming bass – that the band didn’t hear a single complaint.

This eclectic approach is perfectly in keeping with the history of jazz. The music emerged from an unlikely blend of African rhythms and European harmony in New Orleans and evolved with influences as disparate as Dizzy Gillespie’s use of Latin beats to John Coltrane’s exploration of Indian music. “Jazz is an international art form that soaks up things wherever it goes,” Porter says. Previous jazz ambassadors understood this well: Gillespie played sambas in South America; Benny Goodman played a Burmese oboe in Rangoon.

The last thing Porter wanted to do was lecture audiences about American music, or come across as an agent of cultural imperialism. “Someone came up to me and said, `You think America is so great.’ I said, ‘Look, we have problems, but jazz helps us to deal with those problems.’ I always talk about the struggle that created this music – about slavery, and how jazz allowed the underdog to have a voice. I’m certainly not proud of that history, but sometimes beautiful things can be born out of things that are not so beautiful.”

Porter harbors no illusions about what a handful of American musicians can do to spread world peace during a month-long trip abroad; even Louis Armstrong didn’t come home with a nuclear disarmament pact. “I can’t change the way one country views another country,” Porter says. “But if we can play good music that’s open and inclusive, I do believe that can help alleviate tensions that exist with another country. And it shows the world the best of what democracy can be.”

Paul Keegan is a contributing writer for Fortune and Money magazines and has written for The New York Times Magazine, Esquire, GQ, and other publications.