By ANNA BADKHEN
We are in the market square in Djenné, in central Mali. Ali the Griot holds court on a low wooden stool by the pharmacy. He chants:

“The Fulani came from Ethiopia: first the Diallos, then the Sows, then the Bâs. The Bâs had the most cattle; their cows are white; they give the most milk; from that milk comes the sweetest butter.”