Artistic Influences. While most West African cultures of the period 500-1590 had distinct artistic expressions, interregional and trans-Saharan artistic influences were already apparent. Long-distance trade and military expeditions by the North African Almoravids spread not only Islam but Muslim art and culture, which came together with sub-Saharan intellectual and cultural influences at major commercial centers such as Djenne-Jeno and Timbuktu. Some musical forms and instruments of the Sahel and the eastern Sahara bear striking resemblances to those of Islamized cultures in the Western Sudan, part of the band of savanna or grassland stretching across the continent south of the Sahara. Trade, migration, the expansion of kingdoms, and the conquest of neighboring or peripheral peoples within West Africa also brought the commingling of cultural and artistic media, styles, and forms. For example, the complex mythology of the Yoruba-speaking peoples of Nigeria—who had migrated...