“Anne Brown, a penetratingly pure soprano who literally put the Bess in ‘Porgy and Bess’ by inspiring George Gershwin to expand that character’s part in a folk opera that originally was to be called ‘Porgy,’ died Friday in Oslo. … Even after winning the Margaret McGill prize as the best singer at Juilliard, she had no hope in those days of reaching the top tiers of opera,” due to racial discrimination. So the Baltimore-born singer moved to Norway, where she became a citizen.