Engineered languages (sometimes abbreviated to engilangs or engelangs) are constructed languages devised to test or prove some hypotheses about how languages work or might work. There are at least three subcategories, philosophical languages (or ideal languages), logical languages (sometimes abbreviated as loglangs), and experimental languages. Raymond Brown describes engineered languages as "languages that are designed to specified objective criteria, and modeled to meet those criteria".
Some engineered languages have been considered candidate global auxiliary languages, and some languages intended as international auxiliary languages have certain "engineered" aspects (in which they are more regular and systematic than their natural language sources).
The music of Nigeria includes many kinds of Folk and popular music, some of which are known worldwide. Styles of folk music are related to the multitudes of ethnic groups in the country, each with their own techniques, instruments, and songs. Little is known about the country's music history prior to European contact, although bronze carvings dating back to the 16th and 17th centuries have been found depicting musicians and their instruments. The largest ethnic groups are the Igbo, Hausa and Yoruba. Traditional music from Nigeria and throughout Africa is almost always functional; in other words, it is performed to mark a ritual such as a wedding or funeral and not for pure entertainment or artistic enjoyment. Although some Nigerians, especially children and the elderly, play instruments for their own amusement, solo performance is otherwise rare. Music is closely linked to agriculture, and there are restrictions on, for example, which instruments can be played during different parts of the growing season.
Work songs are a common type of traditional Nigerian music. They help to keep the rhythm of workers in fields, river canoes and other fields. Women use complex rhythms in housekeeping tasks, such as pounding yams to highly ornamented music. In the northern regions, farmers work together on each other's farms and the host is expected to supply musicians for his neighbours.