In Airs in Berberland, Part 1: Vibrations in the High Atlas, spontaneous or interpreted music expresses a primeval universe of which water is the central element. For women, singing in high polyphonies, in "youyous" or "ritornelles," accompanies every action; men play flute and frame-drum at nightfall when the villagers assemble to dance a cosmic round dance. In Airs in Berberland, Part 2: Nuptials in the Middle Atlas, tribes get together to sing and dance the mythical nuptials that embody the forces of vegetation, and all the hopes of abundance and fertility. Gnaouas shows how black Africa flows in the veins of Morocco. Pre-Islamic culture mixes with rites of African divinities in the ceremonies of spirit possession and exorcism of the brotherhoods of Gnaouas, descendants of Africans who came to Morocco as slaves in the fifteenth century. The ceremonies are accompanied by the bass of the great "haihouj" lute and other instruments. Malhoune signifies the "song of the dialectical word." These songs sung daily in Marrakech and Meknes are similar to classical Moroccan poetry in their lyrical and rhythmic structure, and represent the common expression of popular wisdom and everyday reality.