 The interior of the Gesu was a study of the grandeur that Roman classicism could offer when combined with simplicity in large scale.High windows puncture the nave's barrel vault, as a ring of windows in the drum of the dome bring beams of natural light into the interior, creating a dramatic contrast of light and darkness in relatively dim space.The plan of Il Gesù became the standard for churches for years to come; a breakaway from the ideal central-plan church of the Renaissance into something new.