Naturally, work songs take on the qualities of the work they accompany. In Africa, for example, collective work songs are not all that common in the rain forest belt, which includes the Yoruba, Ewe, Ibo, and other tribes and corresponds roughly to the main drumming area. Forest crops generally need less communal labor than field crops. As a result, the more open savanna belt of West Africa has more group work songs than do the forests. But even in the savannas work songs often are supplied by professionals who play music to encourage, rather than direct, the labor. These musicians or singers do not take part in the work — or, rather their part in the work is their music.
