This was a bizarre, compelling and somewhat chaotic event, better suited to a desert festival than a sedate South Bank concert hall. On to the stage paraded four men and a woman, all bashing away at a variety of hand drums and followed by a matronly lady in her mid-50s wearing white robes, white headscarf and glasses. She sat on a stool, picked up an acoustic guitar and, looking like north Africa's answer to the Singing Nun, picked out a part-Arabic, part-bluesy melody on single strings.
The drummers increased the tempo and the volume, the audience clapped and yelled, and the lady in white began to improvise around the guitar riff. It sounded more like the finale than the opening song.
Hasna el Becharia is a remarkable woman: an Algerian living in France, but with a very different approach to her successful exiled compatriots. She is influenced by family tradition, the music of the Gnawa from south of the Sahara, whose trance-like music has been used for centuries to heal the sick. Even in Paris, Hasna works with women who have been abused, and plays for those who are troubled or ill.
She is no ordinary musician, then, and this was no ordinary concert. After showing off her gutsy guitar work she then demonstrated her equally powerful vocals. Next, she moved to the guimbri, a box-like guitar with an earthy, clonking bass sound. This is traditionally played only by Gnawa men, so Hasna could play it publicly only after she moved to France. Finally, and most incongruously, she plugged in an electric guitar and continued to pump out those slinky riffs, while the hand claps and percussion continued to clatter around her.
The audience were now on their feet and dancing, and one of the percussionists started running maniacally around the stage, banging away at large metal castanets and almost sustaining an injury as he fell over a chair. The more chaotic the situation around her, the more relaxed Hasna appeared. She walked off stage without an encore as a compere announced the results of a raffle to benefit victims of the Algerian earthquake. It had been an odd, exhilarating evening.