On 20th February in Barbican, London, Mali's Oumou Sangare restated her indisputable prominence on world music stage. She moves crowds of all races and classes. Her music is rooted in her native Wassoulou tradition. Poets and stockbrokers, doctors, filmmakers, computer wizards and policymakers, fashion designers, students are all searching for ideas to stay ahead of the rest. They know world music concerts have answers.

Since Nigerian music allowed hip-hop to be its defining expression, when most Nigerian artists perform, they think they can out-rock Metallica, out-rap Jayz or out-dress Snoop Dogg. With no band to lead, they bounce tastelessly across the stage, screaming desperation into microphones. Yet it is from a band that you investigate the mastery behind each instrument and its degree of rapport within the group; from there you gauge the musician's intelligence and creativity. ÔÇśWhen I perform you see Africa on stage.' Oumou says.

Born in Bamako 42 years ago into polygamous setting, Oumou's father abandoned her pregnant mother for another woman when she was 2. By 5, dented by hunger, she sang for pay at parties. She gave up childhood to be her family's breadwinner. ÔÇśI can face any obstacle,' she now declares. At 18, Miriam Makeba asked her to recruit a band and take charge of her destiny. By 21, she became an elephant that flew. Her first album compelled attention as a document of gut in a society where suppression of women's growth is status quo. She hit at arranged marriage, polygamy, female circumcision, robbing girls education and other zerofication of women. She sang openly about forbidden topics. 'People had sung about love before, but not about lust.' In Diaraby Nene (The Shivers of Passion), she elevates it to plane of regard. Na Bi Fe (I Love You) recalls Debussy's La Mer; implying women's hearts have the majesty, depth and might of sea. The beginning is a sensuous duet of string instruments: one's poignant lyricism is the osinato, the other flirts around notes before teasing out the choral melody. The backup vocals take this over and sweetened it into a tune of extraordinary delight; flutes shimmer to suggest breezy winds and ambience of sea, Oumou's vocal does not stop but end up tenderly as luscious echoes over dissonances; cymbals crash steadily to suggest rustling sea waves yet this rich, layered orchestration remains tranquillamente. Oumou became an unprecedented annoyance society must reckon with.

Her music is not entertainment but experience, a conscious theatre of ideas. On stage, instead of grouping her instruments according to type, she placed the so-called western instruments to the back and highlighted the traditional at the front such that electric guitars were at the back but their string counterpart, the Kamale N'goli that gives her music that signature was positioned right beside her; congas were at the back but Sabar was in front. Hence, before her night kicked off, rebellion was already on stage. This contradiction between emancipation from tradition and fidelity to it is the driving force of her life and creative principles.

Rich and famous, with a Chinese car brand Oum Sang name after her, Oumou still travels around villages collecting inspirations. Like our Christy Essien Igbokwe who can sing in four cultures, Oumou navigates other tribes' music and emerges winning. A six-footer, she is a figure of strength to women and a social conscience. A government official once resold her land to a farmer. Oumou charged in with a bulldozer and levelled the hectarage to the last crop. Oumou, an international figure, FAO's goodwill ambassador who divides her time between Mali and Paris never misses an opportunity for positive rascality when occasion calls for it.

In Donso, a song about hunting, she enters a male preserve and excels there. She substitutes her female backup vocals with males. When the kamale is quizzed for tune but supplies none, the bass guitar presents its own idea which is accepted as tone for the track. Yes, yes, the kamale sees the point and joins. Not the violins. Instead, they offer their own theme. Then Oumou's incantation takes over like ijala. And the male vocal backs her up as if nodding. Oumou has beaten her masters: Coumba Sidibe, Ali Farka Toure, Salif Keita; her contemporary Issa Bagayogo is not a mile close, Dieneba Seck is wonderful and can emerge as Oumou's nemesis, the younger, scintillating Rokia Traor├ę still needs polishing. Oumou at 42 is the new Miriam Makeba. She has earned the right to be arrogant. Off stage, instead of bodyguards, she maintains a praise singer who chants her oriki 24/7. Why? ÔÇśFor courage,' Oumou says. Her humiliating childhood has made the lack of self-worth an ingrained force to constantly fight against. At Barbican, when not dancing with furious energy, she spread out her arms wide like Moses or strut the stage shaking her maracas with royal deportment ÔÇô all in order to fight that force.

She launched into Wayeina (An Exclamation of Enjoyment) arguably her greatest song. After the kamale headlined, the orchestration, strings, winds, percussion, leapt up at once. What followed was magic, bliss and beauty. Then came Oumou's vocal range startling in its carrying power. She move on to Yala (Roaming about for No Good Reason) another classic and invited the audience to swing to its electrifying tempo like wild gyrations of fire. Breaking down the interface between stage and spectatorship, she taught the audience Weke Wintou from grammy-nominated album, Seya. Hasty in its tempo, the track opens with an audio quote from Fela's flourish of sax and Oumou laments hasty and marriage of underage girls; she stands up for women's freedom of time and choice. Her voice however doesn't attain the usual stratospheric heights; she defers that to the sax.

The audience clapped ecstatically after each performance but it was Governor Modu Sheriff of Borno who years ago modestly gave her a Hummer jeep as the loudest ovation. In Djigui, she returned the compliment. Everything seems right: the instrumentation proceeds harmoniously, the mood is pianissimo; until the flute begins howling like a tormented conscience; then Oumou's reassuring vocal riffs out Modu and Fatima Sheriff's praise as ÔÇśthe hope of women and children of Maiduguri.' Hearing this, the flute, plaintive before, displays exuberantly as if eschewing earlier crisis of conscience. Oumou is too foreign to understand that in Nigeria, politicians donate thousands to charities while robbing the people of billions.

Iyo Djeli is homage to Djekani Djeli a wise, barren woman who later confounded wagging tongues. Oumou swerves to thank her own mother, ÔÇśthe beautiful and dignified Aminata,' asking her to cry no more, forget past sufferings and thank the good Lord for having a child like me.' Oumou does not sing in any colonial language, French or English. As a testament to her ingenuity, one can pick out her meaning carefully listening to the instrumentation's idioms and her vocal dynamics.

With her flair for beginnings, she asks balafon, a native xylophone, to lead tribute to the great one, the violins follow introducing their gracefully brief theme without changing the subject. (In the album, the violins do not accept nor recapitulate to others, they are just self-assertive like the attitude Oumou is prescribing to women.) Then Oumou's vocal fires off more tribute like a space shuttle daring the other instruments to rise up to it. The dare is reminiscent of Sukunyali, the most stylistically rewarding track wherein the duel for top space is between her mind-bending, tear-jerking vocal range and the N'gonis's terrifying Jimmy Hendrix psychedelics. There is no victor no vanquished. Just like her stage performances, she is wise enough to know the closure of possibilities associated with resolutions and gratified longings. She arouses her audience to cloud nine and leaves them there unorgasmed. At Barbican, this was so sweetly annoying.