Angélique Kidjo’s singing career began at the age of six, with her mother’s theatre troupe in Benin, west Africa. But when the military dictatorship forced her to sing for them, “I felt raped in my soul, my free will stepped on,” she recalls. She fled to Paris in the 1980s to become the West’s most successful African diva, a singer-songwriter melding African sounds with jazz and funk, latin and gospel. Yet her message for anyone wanting to harness her voice – whether tyrannical regimes or roots purists sniping at her “crossover” appeal – is clear. “It’s my vision of my music and my culture,” she stabs the air. “Nobody has a right to tell me what to do with it.”

We are sipping herbal tea in a smart hotel in the centre of Paris, though Kidjo, a petite dynamo with a close crop of dyed-blonde hair, now lives mainly in New York. She will be at the Barbican, in London, on September 28 as part of Passage of Music, a series of events marking the bicentenary of Britain’s abolition of the slave trade.

Her new album, Djin Djin, features longtime collaborators Carlos Santana and Branford Marsalis, with song partners including Peter Gabriel, Amadou and Mariam, Alicia Keys, Joss Stone and Ziggy Marley. Kidjo’s powerful voice combines classical and jazz training in Paris with zilin, a blues-like vocal technique from Benin. Most of her songs are in her mother tongue, Fon – including a mesmerising a cappella version of Ravel’s Boléro. “I can sing a cappella any music you give me,” she says. “Traditional musicians in Africa have no microphones – all you have is your ear.”

Djin Djin is a return to her source: “In Benin, the rhythms are so complex.” Finding a flowering of talent there after the return to democracy in the early 1990s, she built the album around traditional percussionists from the Gangbé Brass Band. The album producer, Tony Visconti (veteran of David Bowie and T Rex recordings), was sceptical. She laughs, “I said, ‘Tony, trust me. I know the power of the drums. When they start speaking, you follow.’ ” She says that the “world music” tag “used to make my blood boil. Now I don’t care – I know it’s human nature to try to categorise people in order to feel in charge”. She is also used to annoying the purists, who cast doubt on her authenticity. “I’ve been bashed left and right by people who want to have control. I never fit those clichés. I grew up listening to all genres.” For the musicians of her childhood, “music had no frontiers, no colour, no language – you do what you have to do to touch people’s soul”.

Africans should be unafraid to borrow from American music, she says, since “they’re only taking back what’s theirs”. Her album trilogy, Oremi (1998), Black Ivory Soul (2002) and Oyaya! (2004), traced West African influences along the slave routes into the Americas, from the Deep South to Cuba and Bahia in Brazil. “Everywhere I go, I find a bit of my country and the African continent,” she says. Listening to reggae, she heard traces of the gogbahoun rhythm from her own village, while in samba she heard drumming from Benin’s ceremonial vodu – a term local followers of the ancestral religion prefer to “voodoo”.

“Rock’n’roll would not exist without the blues, which started in the cotton fields. They took the drums away so Africans couldn’t communicate, but we communicated by song.”

It was music that first made her aware of slavery, when she saw an image on an album cover, and asked “how people could be African and American at the same time”. She was born in 1960 in Ouidah, on Benin’s coast, a key port in the slave trade. But at school “everything made for an amnesia. It had to be explained by my grandmother”. Benin was a musical crossroads, from Zairean rumba and Cameroonian makossa, to the samba of slave descendants returning from Brazil speaking Portuguese creole – including Kidjo’s maternal grandfather.

One of nine children, she was introduced by her siblings to rock and Motown, and sang with the Kidjo Brothers Band. But when the 1972-90 dictatorship of Mathieu Kérékou decreed that “all artists had to praise the regime, I said I’d rather die”. Moving to Paris in 1983, she had ambitions to be a human-rights lawyer. “But after three months in law school I thought, I’m better off with a microphone.” After singing with the afro-jazz group Pili Pili in Holland and Germany, Kidjo was signed by Chris Blackwell of Island Records in 1989, and had dancehall hits in the 1990s.

Her classically trained husband, bass guitarist Jean Hébrail, became her producer. They have a teenage daughter, Naima, who plays piano. Her work in the American diaspora “redoubled the pride I had”, she says. “If we Africans could have such a musical influence, then we can use music to have an impact on other issues.” She sees Live8 as a “good idea, but the way it was handled was wrong. If you want to help Africa, you have to work hand in hand with Africans. You can’t be Bob Geldof and tell us African artists can’t play in Hyde Park because people will turn off the television.

It’s taking the public as stupid”.

Kidjo has been a Unicef good-will ambassador since 2002, and recently met French politicians in Paris after visiting Sudan’s Darfur region. “The politicians are realising if they don’t find a solution to Darfur, they’ll be held responsible – unlike the Rwandan genocide,” she says. She has also just launched Batonga, a foundation to pay for girls’ education in five African countries. “When you get that chance in life,” she says, “you’ve got to give back.”

Djin Djin is out tomorrow; Angélique Kidjo plays the Barbican, EC2, on Friday

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