Youssou N'Dour, one of Africa's (and the world's) greatest singers, makes a welcome return to Japan this month. The last time he was in Japan was for the 1994 WOMAD festival in Yokohama. World music was still on a roll back then, with some African artists such as Papa Wemba becoming genuinely "big in Japan." Sadly, as with most fads, the boom inevitably went bust.

The period of mourning seems to be over at last. With top acts such as Nigeria's Femi Kuti, Mali's Habib Koite and now Senegal's Youssou N'Dour visiting in recent months, Japan seems once again to be on the tour itinerary of some big artists.

N'Dour doesn't just have a great voice, he is the voice of modern urban Africa. With his soulful and soaring singing, he can tease out a delectable melody or take up a fervent refrain with that indefinable sense of yearning that just isn't there in most Western music. Around that voice, the tama (talking drum), punctuates across the beat in short phrases, a stick cracks out a rhythm on the sabar drum, while guitars, bass, keyboards and horns add touches of jazz and soul.

Even as a young teenager with Etoile de Dakar, N'Dour, now 40, had a voice that was at once young and ageless. His words are totally relevant to today, the delivery rooted in tradition; in N'Dour's own words, he's "a modern griot."

Born in the poor yet vibrant quarter of Dakar, he grew up a gawlo, or singing griot, through the lineage of his Tukulor (Northern Senegalese) mother. Combining Cuban music with Senegalese traditional music, he sang in his native Wolof, popularizing the music called mbalax, developed in Senegal in the late '70s.

By the early '80s, his group had evolved into Super Etoile de Dakar, and soon their hits were emanating from every market stall, restaurant, nightclub and taxi in Dakar and elsewhere in West Africa. After touring Europe in 1983 with Super Etoile, he built up a cult following and wrote the song "Immigres," a plea for Senegalese emigrants to remember their homeland. The album of the same title, received a European release and reached the ears of Peter Gabriel, who went to Dakar the following year to meet him. The two collaborated on several songs including "Shaking the Tree," and N'Dour traveled the world in 1988 on the Amnesty International "Human Rights Now" tour with Gabriel, Sting, Tracy Chapman and Bruce Springsteen.

N'Dour embarked on two separate careers, one for the home market, the other for an international audience. While his prolific output of cassettes in Africa has been consistently brilliant, his international albums have been disappointingly patchy.

His first album for Virgin, "The Lion," recorded in Paris, consisted mainly of reworked older material and lacked the energy of the original tracks. Despite the much improved second album, "Set," recorded in Brussels, sales didn't match the investment and he was duly dropped by Virgin.

At least this experience convinced N'Dour he would be better off recording future albums in Dakar. He built his own studio, Xippi, and has co-produced his subsequent two albums, which were nevertheless aimed squarely at the Western mainstream market.

On "Eyes Open," recorded for Spike Lee's Forty Acres and a Mule label, N'Dour was able to convey messages about topics he considers important, such as immigration, the environment and feminism, by singing some lines in English. On the next album, "The Guide-Wommat," the first to be entirely produced in Senegal, N'Dour was joined by Neneh Cherry on his biggest hit "Seven Seconds." In retrospect, though, the glossiness of these two albums failed to match the harder-edged mbalax sound on his more recent cassettes for his own Jololi label.

His much delayed (until next year) new international release features Neneh Cherry and Peter Gabriel once again, as well as Wyclef from the Fugees. Purportedly it's not pure mbalax, but more a mixture of styles including Spanish elements and the griot praise songs, called birima.

N'Dour has never forgotten or forsaken his Senegalese roots, family and friends, and many of his songs pay tribute to them. He is Senegal's most famous person, and his name is painted on walls throughout the country. Thousands turn out at Dakar Airport to greet him when he returns from overseas tours, and being Senegal's most traveled ambassador he even offers advice to the country's president. Each cassette release is eagerly awaited, while on the streets of Dakar, new griot mbalax singers are all vying for the title of the new "king of mbalax."

I witnessed the unifying force of Youssou N'Dour while at a club in West Africa earlier this year. The DJ was mixing African and Western dance music which seemed to bring different sets of people onto the dance floor. Only when he played Youssou N'Dour did everyone unite to sing and dance together.