BeauSoleil, Queen Elizabeth Hall

Our story begins in the early 1970s, when a young fiddler from Louisiana named Michael Doucet was making rock music. Then one day he heard a song by Fairport Convention: “Cajun Woman” (from the band’s Unhalfbricking album). He was shocked and delighted that an English group should be taking an interest in a strand of music that seemed to be fading into obscurity. In a sort of Proustian moment, he inhaled the fragrance of “Cajun Woman”, his interest in the music of his native region was awakened, and Doucet began to immerse himself in the folk music of France and of his home state, where French music and culture have survived ever since the influx in the mid-18th century of Arcadian settlers (Cadiens; hence Cajun) from Nova Scotia.

Thus were born BeauSoleil, the Cajun band who over the subsequent decades have not only kept the music alive, but stretched it and pushed it into new realms. And thus the presence of BeauSoleil at this year’s Southbank Meltdown festival, curated by the folk-rock legend and former member of Fairport Convention, Richard Thompson, these days an old friend.

So much for the history lesson; now for the music. BeauSoleil traipsed on stage looking quite unlike a band of musical visionaries – gnarly, white haired, tufty and unprepossessing. But instantly they made an impact, as Doucet (pictured right) and fellow fiddler (and bassist) Mitchell Reed duelled and duetted as a prelude to the main event, their violins thrumming and dovetailing immaculately. Then drums, percussion, guitar (played by Michael’s brother, David), and – vitally – accordion kicked in: instant magic. In all of music, there is no sound like it: Cajun music has its own rhythms, its own textures, its own sound, even its own language (French, but heavily Americanised). Cajun standards such as “Bon Temps Rouler” were dusted down and given a fresh coat of paint by the band, whose approach was respectful but not slavish to tradition. Doucet may be a dedicated custodian of Cajun music, with a broad and deep knowledge of the culture and the folkore, but this was no mere academic exercise: this was real, live, contemporary music.

Then came a lovely surprise (though it was less of one for those of us who had spotted an unused Fender amplifier and a spare microphone on the stage). Doucet introduced to the stage Richard Thompson, in combat trousers, baggy shirt and baseball cap; inevitably they played “Cajun Woman”, decorated with note-bending flourishes from Thompson’s inimitably jangly-spangly Stratocaster.

“Conja (New Orleans 1786)” was jumpy and sharp; “La Fille de Quatorze Ans” was a characteristically tragic story-song (albeit one in which the story had to be relayed to the audience beforehand for the benefit of those whose French was a bit rusty). Thompson stayed out of the limelight, but gave little glimpses of his fretboard brilliance. He remained on stage for a couple more songs, then left them to it.

And so it went on. There were waltzes, there were two-steps, there was blues (a version of Muddy Waters’ “Rollin’ and Tumblin’”, from their recent Alligator Purse album); there was even a bit of jazz, when Doucet’s fizzing violin brought to mind the great Sugarcane Harris. Mention, too, should be made of the exquisitely subtle and unostentatious accordion-playing of Jimmy Breaux.

The pleasure and satisfaction of this show chiefly came from the music, but also from the sense that, vicariously, it was giving us a glimpse into another world, another culture. It was a pity that the all-seater venue precluded dancing, but those who still had the urge to do so after the show were rewarded with a second set in the foyer from the lovely support band, Sarah Savoy and the Francadians. Fiddle, bass, accordion, guitar, voices, percussion: there is nothing like it for quickening the pulse.

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Watch BeauSoleil perform "Theogene Creole"