Youssou N'Dour and the Fathi Salama Orchestra, Barbican, London

Dakar-born singer Youssou N'Dour is one of a generation of West African music stars to cross their own native traditions with the music of the Caribbean as it returned to source in the first years of African independence. Later the dominant templates of pop, rock and soul provided the fuel to forge their international reputations. Just as Griot singer Mory Kante reached a new world audience with the dance floor hit Yeke Yeke in the 1980s, so Youssou went international via collaborations with Peter Gabriel and Paul Simon, and later with Neneh Cherry on 1994's huge international hit, Seven Seconds.

Recently, however, the likes of Mory Kante, Kasse Mady and Salis Keita have returned to the acoustic roots of their music, and with his album Egypt, recorded in Cairo and Dakar in 1999 with the Fathi Salama Orchestra, but not released until this summer, Youssou N'Dour has crossed the Maghreb to combine the sounds and instruments of West and North Africa.

The album's live debut was at this year's Festival of Sacred Music in Fez, and though the Barbican may not be as thrilling a setting as Morocco's medieval second city, Youssou's spectacular devotional music - the Senegalese title of the album is Sant Allah (Thanks God) - conjures a medina of the mind with a seamless 90-minute performance that builds upon the eight songs from the album. It's the second of two UK concerts in a tour that takes in Europe, then America, a year after he cancelled his biggest ever tour there in protest at the invasion of Iraq.

With Egypt, Youssou has left behind his Afro-Cuban mbalax (rhythm) music for a tapestry of sound that combines sweeping Arab melodies with pulsing, interweaving West African percussion. His voice, with its warm, intimate tones, remarkable range and intense humanity becomes a vehicle of faith in a cycle of songs that praise the mystical Sufi schools of Islam that have centred post-independence life in Senegal.

Tonight's music is a previously uncharted synthesis of ethnic forms. Strings, woodwind, oud, flute, balafon and kora combine with a panoply of Senegalese and Arabic percussion and the vocals of Youssou and his chorus, to create a luminous sea of sound that carries the audience far beyond the confines of the Barbican hall, the blending of musical cultures a dazzling tour de force.

It is five years since Youssou has played the Barbican, and since he recorded Egypt much has changed for the worst, yet this concert returns as forcefully to the unifying spirit of a music that ranks with the best in the world.