African art is extremely diverse as Africa is made of thousands of different cultures, religions, civilization etc. However, there are some common themes that can be found in African art. These themes include: Emphasis on the human figure, visual abstraction, sculpture, and emphasis on the performing arts.
This is of course a massive question and any attempt to identify one African culture is doomed for failure, as Africa encompasses so many different cultures and nations and vast geographical space. However, as regards to literature, you might like to look at the work of such authors as Chinua Achebe and N'gugi wa Thiongo, both of whom are very important African authors who write about the very bitter experiences of colonialism and their aftermath.
Two features of African art that do unify differentiated art of disparate cultures are the prevalence for abstraction of shapes over naturalism in shapes, and the preference of images of the human form. Another unifying feature is the fractal-like designs that reflect in a single portion the pattern of the whole--similar to a holistic image in which the part mirrors the whole.
This question is difficult because Africans do not share a universal cultural history. There are thousands of unique cultural groups in Africa, each of which is constituted by a robust cultural history of its own. Africa has a history of imperialism and colonialism, and the boundaries separating nations have not always coincided with the land boundaries of specific ethnic groups. In the latter half of the 20th century, African leaders began breaking away from their European colonists. They developed ideas of racial and political solidarity. These ideas form the root of a shared African identity. One such idea, popularized by African heads of state like Kwame Nkrumah, is pan-Africanism: the idea that all Africans should unite to resist colonialism and secure independence. Much African literature, music, art and religious expression from the 1940's onward centered around ideas of pan-Africanism.