Life's seldom dull for Michael Ward-Bergeman. A few days into the latest tour by his group, The Groanbox Boys - which brings the trio's country blues-Appalachian folk-Eastern European gipsy cocktail back to Scotland this weekend - the London-based Long Islander is taking a break to work on a piece he's composing for leading American soprano Dawn Upshaw.

The work, commissioned by the Carnegie Hall, no less, is due to premiere in the prestigious New York venue on November 2 and follows Ward-Bergeman's previous Carnegie Hall commission, Three Roads, which was first performed there in April last year. Later in the year, Ward-Bergeman, who along with the amazing Finn Kimmo Pohjonen is also spearheading the accordion's rise as a cutting-edge contemporary instrument, is due to fly off to Argentina, where he'll work on the soundtrack to the next Francis Ford Coppola movie.

Much of this varied menu of activity has resulted, he concedes, from fortunate circumstances and chance meetings, and, let's face it, it would have taken someone with an extremely lively imagination to have foreseen that buying an accordion in a yard sale could have such spectacular results.

Ward-Bergeman was teaching circus arts - as you do - in his late teens, between leaving high school and going to study piano performance and music synthesis at Berklee School of Music in Boston, when he happened upon his first accordion.

"I'd played piano since I was a kid and the idea was that I'd go to Berklee and get a really solid preparation for working as keyboard player in the pop and rock field, and I actually did that kind of work for a couple of years, bought all the gear, that sort of thing," he says.

"But when I was about four or five my parents had bought me this little reed organ and I was transfixed by the sound it made. It sounded like an accordion, basically, and I hadn't known this, because he died before I was born, but my grandfather had played the accordion. He wasn't a professional musician, just played at parties and stuff, but maybe there was something in the genes."

When he got to Berklee, Ward-Bergeman discovered that he was the only person - student or professor - in the whole school at the time who played accordion, and his phone started ringing. Whenever an accordion was called for, whatever the style of music involved, he was the go-to guy. This led to all sorts of experiences, including being sidetracked into the world music studies department, although the experience that really changed his life was a five-hour accordion lesson from Ionita Manole of the brilliant Romanian gipsy troupe Taraf de Haidouks.

"After that, I was gone," he says. "I fell completely in love with gipsy music and even went to Romania to study it."

Oddly enough, it was the Taraf de Haidouks connection that took him into the world of contemporary composition. Having somehow graduated in his chosen subjects, despite the distractions, he was trying to resist using his music technology qualifications to earn a living in recording studios, which seemed to be the way most of his co-students were heading, when a go-between asked if he'd help Polish composer Osvaldo Golijov set up a computer music studio.

Golijov turned out to be a good friend of Taraf de Haidouks and he and Ward-Bergeman got on famously. They worked together on a BBC documentary about Auschwitz - Ward-Bergeman's wife is British, hence his relocation to Walthamstow - and it was through Golijov that Ward-Bergeman got to meet and work with Dawn Upshaw and Francis Ford Coppola.

Meanwhile, another catalyst had entered the picture, the Freedom Boot that plays a big part in the Groanbox Boys' stompin' music. The idea of an accordion and banjo duo, as Ward-Bergeman and Cory Seznec were before percussionist Paul Clifford joined them, was outlandish enough in some people's eyes. After all, accordionists and banjo players are the butts of more jokes than even drummers. But to add an instrument that had been inspired by Morris dancing could have been beyond the pale - or even the pole, in this case.

Ward-Bergeman was camping in Swanage in Dorset during the weekend of the local folk festival when he spotted a Morris dance team with this broom handle covered in bottle tops with a baby's boot on the bottom. He was immediately covetous; as who wouldn't be, he says. So he and Seznec decided to make something similar and incorporate it into their act. The name Freedom Boot comes not, as many have assumed, from them being Americans; they called it that because they persuaded the owners of the Freedom brewery in Staffordshire to give them 450 bottle tops from their Freedom organic lager to pin to their pole.

All sorts of other items have since been appended. There's a bag attached that contains a golden eagle talon and two lion claws sent by a fan in Inverness, and Clifford appropriated wood cuttings from the Door of Angst in Stirling's Tolbooth arts centre, where in its previous service hangings took place.

Neither of the original Groanbox Boys believes in mojo or the dark arts particularly, but the boot has taken on a life of its own and helped to cement Ward-Bergeman's friendship with British-American composer David Bruce, who was so fascinated by it that he built his own and featured it in his composition, Piosenki, at Carnegie Hall last year. Now Freedom Boot building - and decorating - is a growing pastime in certain circles.

"It was just a novelty as far as we were concerned," says Ward-Bergeman, "but people see it and come up and say, Oh, you must be from Australia because that's a lagerphone'. Or they think we're German, because they have them there, too. And, actually, now that we've done some research, they had them all over the world going back 2000 years or more, and they would ward off evil spirits or inspire armies going into battle. It's a percussion instrument to us but between all the stuff that people have given us to put in the bag and all the theoretical and historical stuff that's been attached to it, it's become pretty heavy both physically and spiritually." The Groanbox Boys and their Freedom Boot appear at The Tall Ship, Glasgow, on Sunday September 7; The Village, Leith, on Monday, September 8; Old Library, Kilbarchan, on Tuesday, September 9; The Courtyard, Kenmore, on Wednesday, September 10; and Acoustic Music Club, Kirkcaldy, on Thursday, September 11.