These social strata, like caste systems found in many parts of West Africa, included singers, musicians and story tellers of the Tuareg, who kept their oral traditions. They are called "Agguta" by Tuareg, have been called upon to sing during ceremonies such as weddings or funerals. The origins of the artisanal castes are unclear. One theory posits a Jewish derivation, a proposal that Prasse calls "a much vexed question". Their association with fire, iron and precious metals and their reputation for being cunning tradesman has led others to treat them with a mix of admiration and distrust.