In the Sahara as elsewhere in North Africa, popular religious observances often include elements of pre-Islamic faiths in their ritual; the most salient example is the institution of religious dancing, which persists despite long-continued discouragement of the custom by educated Moslems. Even in the highly religious settlement of the M'Zab, where the puritanism is carried to excessive lengths, the holding of dances is not unknown.
At the time I lived there children were not allowed to laugh in public, yet I spent an entire night watching a dozen men dance themselves into unconsciousness beside a bonfire of palm branches. Two burly guards were necessary to prevent them from throwing themselves into the flames. After each man had been pulled back from the fire several times, he finally ceased making his fantastic skyward leaps, staggered and sank to the ground. He was immediately carried outside the circle and covered with blankets, his place being taken by a fresh adept.
There was no music or singing, but there were eight drummers, each one playing an instrument of different size.
From Paul Bowles, Their Heads Are Green And Their Hands Are Blue: Scenes From The Non-Christian World.. New York, Random House, 1963.