It stands 49 metres tall at the western tip of Africa. The costly bronze statue, on a hilltop overlooking the Atlantic from Dakar, Senegal, is meant to symbolise continental renaissance. Critics regard it as a symbol too – of another African leader who has lost the plot, consumed by hubris.

Who, then, will challenge its builder, Abdoulaye Wade, the octogenarian president set on clinging to power beyond his time? Step forward Youssou N'Dour, spine-tingling singer, composer, occasional actor, entrepreneur, political activist and now would-be saviour of Africa's latest imperilled democracy.

The 52-year-old has suspended his lucrative recording and touring career to take up his "supreme patriotic duty" of running for president in next month's Senegalese elections. Accusing Wade of "hearing only in mono, not stereo", N'Dour says he is answering the demand of the people for an alternative.

From Later… With Jools Holland to the political front line: time will tell whether this will also go down as an act of hubris. Gloriously gifted, N'Dour is the undisputed king of Senegalese music, mixing the country's traditional mbalax with everything from Cuban rumba to hip-hop, jazz and soul. His prolific output sings of Africa's identity, heritage and hopes, sometimes with a political edge. He is arguably the most important figure in world music.

And he is famous for much more than being famous: the embodiment of the self-made man, he is feted at home as an entrepreneur and job-creator, owning two recording studios, a micro-finance company and a stake in a leading nightclub. He is a media mogul with television and radio stations and the widely read L'Observateur newspaper. "I have more than a thousand people working for me," he told the BBC last week.

His political credentials doubtless make him palatable to the west. N'Dour campaigned for the release of Nelson Mandela, performed at concerts for Amnesty International and Live 8 and is a Unicef goodwill ambassador, a role he has temporarily stepped aside from while he campaigns. But his change of gear now, plunging into the hurly-burly of domestic politics, is something else. It could be described as analogous to Bob Geldof or Bono running for taoiseach.

N'Dour told the Guardian four years ago: "I want to use my music to deliver a political message… but I don't want to be a politician. In politics, sometimes you have to lie, or you make a promise that you cannot keep. If you play a political role, you have to stop being an artist."

He will hope his celebrity brings greater success than it did for George Weah, the former world footballer of the year, defeated for the Liberian presidency in 2005, or for Afropop pioneer Fela Kuti, who announced plans to seek Nigeria's top position in 1979 and 1983 but was disqualified both times. N'Dour is a late entrant to a crowded field and his political nous is questioned.

"For the last 20 to 30 years, this man has been able to express the feelings of the Senegalese," said Mamadou Diouf, a Senegalese academic and director of the Institute for African Studies at the Columbia University School of International and Public Affairs in New York. "But how is he going to move from the claim, 'I am not a politician' to a genuine campaign for political office?"

Diouf believes the musician has an uphill task to win the election, arguing that he lacks organisation and that Senegalese voters tend to prefer their leaders university educated in the western tradition. Senegal was the first of France's west African colonies; residents of its four main towns were granted French citizenship. Léopold Senghor, the first president, was considered one of the 20th-century's finest lyric poets in French.

N'Dour does not even have a school certificate. He was born in a working-class suburb of Dakar, the eldest child of a car mechanic, and began by hustling pirated CDs in car parks. "It's true that I haven't pursued higher education," he admitted last week, adding: "I have proved my competence, commitment, rigour and efficiency time and time again. I have studied at the school of the world."

Despite his father's wish that he pursue law or medicine, N'Dour started singing at circumcision ceremonies before his voice had broken and was professional by the age of 13. With a voice that seemed heaven-sent, he sang in small clubs in Dakar in Wolof, the language of his griot (praise-singing) ancestors, and was rapidly crowned "Le petit prince de Dakar".

In 1979, he formed his own ensemble, the Etoile de Dakar. Their early work was in a Latin style popular all over Africa then, but in the 80s he developed a unique sound when he started his current group, Super Etoile de Dakar.

It was then that Peter Gabriel, the former Genesis singer turned producer and promoter, flew to Paris to hear N'Dour perform to a Senegalese audience. "I was blown away," he told the Observer. "The words that came to mind were liquid gold. A fluid and expressive voice."

N'Dour appeared on Gabriel's platinum-selling So album in 1986 and joined him on a subsequent world tour. "He's probably the top African artist in many ways. His music has reached a lot of people outside his culture. He's also become something of a statesman with all the campaigns he's taken on."

Gabriel, who is godfather to one of N'Dour's sons (the singer reciprocated with Gabriel's son), said N'Dour is probably the best-known person in Senegal. "When I was there, whenever I was stopped by police or asked for a bribe, I identified myself as a friend of Youssou and the problem generally disappeared."

But the notion that N'Dour could do for African music what Bob Marley did for reggae looks difficult to sustain. Musically, there have been hits and misses. He collaborated with Paul Simon and Branford Marsalis and his duet with Neneh Cherry, "7 Seconds", was one of the bestselling songs of the 90s. Twice, however, he has been dropped by major labels, struggling to balance African and western tastes.

Political rivals should heed his resilience, however. He won a Grammy in 2005 for Egypt, an album of Islamic praise songs. N'Dour is a member of the country's most powerful Sufi brotherhood, which will do his election chances no harm. He told Observer Music Monthly in 2004: "I'm a modern Muslim. I pray, and if I have a question, I ask someone who is more educated in the religion than me. But for me bringing religion into politics is wrong and it shouldn't be necessary to kill even one person in the cause of Islam."

Egypt was interpreted as a political statement in the post-9/11 world and N'Dour cancelled a major US tour after the Iraq war. In 2006, he was the only black actor in Amazing Grace, Michael Apted's film about slavery. As a goodwill ambassador for Unicef, he has focused on African issues such as the Darfur crisis, broadening internet access and the famine in Somalia.

N'Dour once supported Wade and sang for him during official visits before they fell out. The president's 11-year reign has been soured by widespread allegations of corruption, nepotism and erosion of free speech. He tried that old trick – amending the constitution – to all but guarantee himself a third term, only to be knocked back by a wave of protest.

N'Dour's bid to restore the democratic shine is no publicity-seeking whimsy, according to Richard Dowden, director of the Royal African Society. "Youssou N'Dour is a really serious guy," he said. "He genuinely cares about the music and gets involved in the causes. "

Critics take a different view, arguing that N'Dour is running for president to protect his businesses from Wade. When he applied for a licence to open his TV station, approval was held up for two years and he was then ordered to limit its programming to "cultural" matters. Diouf suspects that it may be commercial interests, not change-the-world idealism, which prompted N'Dour to enter politics now.

Indeed, the pragmatic N'Dour risks being seen as more Cliff Richard than Occupy Wall Street. He is most popular for the mbalax beat, a traditional style that does not necessarily resonate with the under-25s who make up about two-thirds of Senegal's population.

They favour hip-hop and it is rappers who have taken the lead in agitating against Wade. Diouf added: "N'Dour is 52. He's part of the old group. He's no longer a social interpreter; he's now a well-established artist and entrepreneur. The rappers are playing the most important role against President Wade."

Should he win, however, this voice of change will have real power for the first time. What would he do with it – and what would it do to him? Gabriel admitted: "I have mixed feelings. In politics, it's hard to remain pure. It isn't easy to be president of any country. He's a reluctant politician. He never had political ambitions when I was working with him.

"It's out of desperation this time. People feel betrayed and they identified Youssou as the only one popular enough to remove the one responsible. I'm worried for him, but I'm also hopeful. He has great heart and an absolutely pure passion for his country and I hope that will carry him a long way."