Eleanor Parker, who was nominated three times for a best-actress Oscar but whose best-known role was a supporting one, as the marriage-minded baroness in “The Sound of Music,” died on Monday in Palm Springs, Calif. She was 91. A family friend, Richard Gale, told The Associated Press that the cause was complications of pneumonia. Ms. Parker was an elegant, ladylike yet sensual film actress. Still, her most recognizable role, as the Baroness who loves Christopher Plummer’s character, Captain von Trapp, in “The Sound of Music” (1965), called for an icy demeanor. Uninterested in his houseful of children, she loses him...