Once a decade, it seems, a record emerges from the dense and vibrant undergrowth of the world music scene to achieve mass popular success in the mainstream. Back in the 1980s it was the Gypsy Kings. In the 1990s it was Buena Vista Social Club. And now it's the turn of the West African duo, Amadou and Mariam.

We live in an excitable world in which words like 'sensation' and 'phenomenal' have been devalued by overuse. Yet it's hard to avoid such vocabulary when talking about the success of Amadou and Mariam's album, Dimanche à Bamako (Because Music). Released in France in November 2004, by last summer the record had risen to number two in the French charts, leaving the likes of James Blunt, Coldplay, Green Day and Mariah Carey all trailing in its wake - the highest chart-placing ever achieved by an African record anywhere in Europe.

Effortlessly funky yet full of insanely catchy tunes and with the African core of Amadou's stinging, snaking guitar lines and Mariam's hypnotically soulful voice tweaked with touches of reggae, jazz, blues and rock, Dimanche a Bamako has now sold close to 500,000 copies around the world and is still gaining momentum.

In Britain, a clutch of five star rave reviews greeted the album's release in summer 2005.The Evening Standard dubbed Amadou & Mariam "Africa's funkiest band." The Observer called their music "the fizziest Afro-pop blues ever bottled". Time Out simply declared they had made "THE world music album of the year." Yet what was even more interesting was the way that the record transcended the usual confines of the world music ghetto. It was acclaimed in the indie rock magazines that usually ignore any record that isn't sung in English by skinny white boys with cool poses, and The Sunday Times, instead of burying it at the bottom of the page where world, jazz and folk albums are usually hidden, boldly declared Dimanche a Bamako "pop CD of the week." Yet perhaps the most telling comment of all came in The Guardian. "Just occasionally," the paper observed, "the right people get the break they deserve."

It's now 28 years since Amadou Bagayoko and Mariam Doumbia met in Mali and started making music together. Mariam had grown up singing at weddings and traditional festivals while the teenaged Amadou had cut his teeth as a guitarist in Les Ambassadeurs, one of West Africa's hottest and most legendary bands. Both are blind and they met in 1977 at the Institute for the Blind in Bamako, where they were both studying Braille and found themselves performing together in the institute's Eclipse Orchestra. They married in 1980, the same year they played their first official concert together as a duo.

Frustrated by the lack of opportunities in Mali, in 1986 they moved to Abidjan, the capital of neighbouring Côte d'Ivoire, where they made their first recordings, on a series of cassette-only releases. Following the success of Dimanche a Bamako, these are now being issued by Because Music on CD for the first time as the single disc collection 1990-1995: The Best of the African Years (1990-1995: Le Meilleur des Années Maliennes) which is due 20th March 2006. This will be followed later in the year by a special box set featuring all five of their African cassette releases 1990-1995: The Complete African Years (1990-1995: LIntégrale des Années Maliennes).

The cassettes made them stars back home in Mali and also reached the ears of a leading French producer who in the mid-1990s suggested they relocated to Paris. Between 1998 and 2002 they recorded three major label albums - Sou Ni Tilé, Ge ni Mousso and Wati - that made them favourites with world music audiences and fans of African music around the globe.

One of those who was suitably impressed was the maverick hit-maker Manu Chao, whose own 1998 album Clandestino was a landmark in global Latin fusion. He was particularly taken with a track called 'Je T'Aime Mon Amour, Ma Chérie', which persuaded him that Amadou and Mariam had the potential to reach a far wider public than the specialist world music audience that had bought their records to date.

"I fell in love with that song and its melody," he recalls. "For a year I played their records round the clock. What I liked most about them was the juxtaposition of the African blues-rock they play and the overwhelming softness they project."

A meeting was arranged in a Paris studio and Chao offered to produce their next album. The result was Dimanche à Bamako. Recorded in both Paris and Bamako, Chao's presence and production cleverly enhance rather than blur Amadou & Mariam's own musical vision, in much the same symapthetic way Ry Cooder worked with the veteran Cuban musicians on Buena Vista. In short, it was a marriage made in musical heaven. Chao had sprinkled his "magic dust" all over the album, The TImes observed. But it wasn't a takeover, but a genuine collaboration. "He brilliantly tweaks what they do, though thankfully not enough to make it sound like his own albums," Mojo astutely noted of his contribution.

Since the release of Dimanche à Bamako, the lives of Amadou and Mariam have changed dramatically as they have made the transition from world music cult heroes to full-blown pop stars and their album has become the most celebrated African record since Youssou N'Dour's Seven Seconds more than a decade ago.

In France, they won a prestigious Les Victoires de la Musique award, the French equivalent of a Grammy, they were nominated for a Prix Constantin the equivalent of a Mercury and the album has now reached platinum. In Britain, they launched the album in the intimate surroundings of the Marquee Club, appeared on BBC2 TV's 'Later With Jools Holland' and then returned in triumph for their first headlining UK in September, when they were nominated for a XXXX MOBO Award and when they packed out the Shepherd's Bush Empire. They have just been nominated for a BBC Radio 3 Award for World Music, the results of which will be announced at an Award Winners concert at The Brixton Academy in April 2006.

A special remix of Couliably from the album by Fred Chichin was selected to feature on the Warchild charity's download website (www.warchildmusic.com) and played on BBC Radio One, whose Zane Lowe called it "the sleeper hit of the summer". MORE ON REMIX CAMPAIGN Urban mixes KANO, AKON, Club mixes BEEDLE, FUTURE WORLD FUNK.

In August 2005, Dimanche a Bamako was released in America via Warner's imprint Nonesuch to another round of rave reviews and is selling in unprecedented quantities for an African record in the US market.

Amadou and Mariam are due to return to the UK in February 2006 for a twelve date 'African Soul Rebels UK Tour 2006 with Souad Massi and Emmanuel Jal.

A DVD featuring a live film shot at La Goutte dOr in Paris and a 26 minute documentary of their recent US tour, plus an exclusive live CD recorded at La Goutte dOr and Park West Chicago will be released on Because Music XXwhenXX.

A case of Sunday in Bamako - and then the world.