"Djelimady Tounkara has powerful hands. His muscled fingers and palms seem almost brutish to the eye, but when he grasps the neck of the guitar and brushes the nail of his right index finger across the strings, the sound lifts effortlessly, like dust in a wind. In Bamako, Mali, where musicians struggle, Djelimady is a big man, and all of his family's good fortunes flow from those hands."Djelimady Tounkara is only one of the memorable people you will...