Fifteen years ago, at the age of 90, Brooke Astor issued a letter to her executors in which she laid out instructions for her funeral. Her second husband, Charles Marshall, had done the same thing before his own death in 1952, “and it was a great comfort to know that I was doing exactly what he wanted,” she wrote. Mrs. Astor, the socialite and philanthropist who died on Monday, expressed her wishes for “a regular Episcopal service” at St. Thomas Church, on Fifth Avenue and 53rd Street, and went on, in the letter, to make specific requests for hymns, prayers,...