Gnawa

Gnawa (plural of Gnawi) were originally descendants of former slaves from original populations originating from Sub-Sahran Africa (Guinea, Niger, Mali, Senegal, Sudan,...). Gnawa term is associated to music but it is more than that. Gnawa has two important meanings. It is used to define both a religious/spiritual order and a music style connected to this order. In the 11th century, slavery, conscription and trade brought people from West Africa region to Morocco. Gnawa brotherhood which is structured around a Mâalem (master musician) instrumentalists, Mquadam and showy (chouaafa in Arabic), mediums and simple followers play a social and spiritual role as well as perform entertainment. Gnawa music is spiritual music that is significantly used for therapy. 

Gnawa of Morocco: A Sample of Historical Photos

Gnawa of Morocco in 1920s: 
Gnawa Music instruments: Tbel "drums" (center) and Krakeb "sort of rattlesnakes" (left and right)

Gnawa of Morocco other photos
Gnawa Music Instruments: Guembri "three-stringed bass lute-drum" (center), Tbel and Krakeb (right), and krakebs (left)