Daara J then provide a complete contrast, the three front men leaping around the stage with an infectious but ultimately exhausting energy that defies both the planet's gravity and their own. On disc, they combine their influences into something distinctively African - Boomerang has been called the first true African hip-hop record - but live, with an impassive French DJ providing the backing, the models shine through more clearly. There are heavy dollops of reggae and ragamuffin, and only occasionally does everything break forth with the full sonic assault of a Bomb Squad. But they bully the reluctant audience to its feet and set everyone dancing and chorusing along. The melancholy that underlies their songs ("Exodus" deals with young Senegalese emigrating) is flattened out, but everyone is left suitably breathless.

Rachid Taha is left with a hard act to follow. Stage right, he has a professorial oud player and a darbuka; stage left, a bank of synths and a vinyl-clad French lead guitarist. Taha himself, a punk-rai bad boy, explodes out of the space between them, much as his music plays off the tensions between traditional Algerian song and the seductions of western rock. Taha starts slouched on a stool in beret, shades and a jacket, his growling rasp oddly reminiscent of Shane McGowan in his cups, but throws off the jacket and the stool to reveal a purple shirt and a series of rock god shapes. A storming version of "Rock El Casbah", his Arabic reclamation of the Clash's orientalist anthem, brings the house down, and his own fusions of rai and heavy metal, such as "Ya Rayah" and "Barra", swoop in majestically behind it. Again, subtlety loses out to volume, but Taha remains a world-class showman.

"Hip-hop," say Daara J, "began in Africa and went out like a boomerang to America. Now it's coming home." All three acts on this tour take styles we think of as western - guitar blues, punk, metal, hip-hop - and play them back through African ears, mutated into something strange and rich. There could be no better introduction to African music, or to the way music evolves and flourishes.

-David Honigmann