Arthur Boyd Hancock III (born February 22, 1943, in Nashville, Tennessee) is an American owner of Thoroughbred racehorses, the owner of Stone Farm, a 2,000 acre (8 km²) horse breeding operation in Paris, Kentucky, and a composer of Bluegrass music.Hancock is a member of one of the pre-eminent American horse racing families. His grandfather, Arthur B. Hancock (1875–1957), founded Claiborne Farm, his father, Arthur B. "Bull " Hancock, Jr.