The Newport Music Festival officially kicks off on Friday with a performance by Boston’s self-conducted orchestra A Far Cry, and over the following seventeen days the festival features concerts in thirteen of the island’s grandest mansions and churches. Today’s big events include a performance of Rachmaninoff’s All Night Vigil, widely considered the composer’s greatest choral work, at the church where JFK and Jackie got married. This event is offered at a “Special Festival Stimulus Price,” perfect for those of us who might be overwhelmed by the dozens of concert options.