The term African art does not usually include the art of the North African areas along the Mediterranean coast, as such areas had long been part of different traditions. For more than a millennium, the art of such areas had formed part of Islamic art, although with many particular characteristics. The Art of Ethiopia, with a long Christian tradition, is also different from that of most of Africa, where Traditional African religion (with Islam in the north) was dominant until relatively recently.
Nok terracotta, 6th century BC–6th century CE
Most African sculpture was historically in wood and other natural materials that have not survived from earlier than, at most, a few centuries ago; older pottery figures can be found from a number of areas. Masks are important elements in the art of many peoples, along with human figures, often highly stylized. There is a vast variety of styles, often varying within the same context of origin depending on the use of the object, but wide regional trends are apparent; sculpture is most common among "groups of settled cultivators in the areas drained by the Niger and Congo rivers" in West Africa.
Direct images of deities are relatively infrequent, but masks in particular are or were often made for religious ceremonies; today many are made for tourists as "airport art". African masks were an influence on European Modernist art, which was inspired by their lack of concern for naturalistic depiction. Since the late 19th century there has been an increasing amount of African art in Western collections, the finest pieces of which are now prominently displayed.
Yoruba bronze head sculpture, Ife, Nigeria c. 12th century A.D.
Later West African cultures developed bronze casting for reliefs, like the famous Benin Bronzes, to decorate palaces and for highly naturalistic royal heads from around the Yoruba town of Ife, in terracotta as well as metal, from the 12th–14th centuries. Akan goldweights are a form of small metal sculptures produced over the period 1400–1900; some apparently represent proverbs, contributing a narrative element rare in African sculpture; and royal regalia included impressive gold sculptured elements. Many West African figures are used in religious rituals and are often coated with materials placed on them for ceremonial offerings. The Mande-speaking peoples of the same region make pieces from wood with broad, flat surfaces and arms and legs shaped like cylinders. In Central Africa, however, the main distinguishing characteristics include heart-shaped faces that are curved inward and display patterns of circles and dots.
Eastern Africans, in many areas shorter of large timber to carve, are known for Tinga Tinga paintings and Makonde sculptures. There is also tradition of producing textile art. The culture from Great Zimbabwe left more impressive buildings than sculpture, but the eight soapstone Zimbabwe Birds appear to have had a special significance and were presumably mounted on monoliths. Modern Zimbabwean sculptors in soapstone have achieved considerable international success. Southern Africa’s oldest known clay figures date from 400 to 600 AD and have cylindrical heads with a mixture of human and animal features.
(source)