I would like to visit the factory that makes train horns, and ask them how they are able to arrive at that chord of eternal mournfulness. Is it deliberately sad? Are the horns saying, Be careful, stay away from this train or it will run you over and then people will grieve, and their grief will be as the inconsolable wail of this horn through the night? The out-of-tuneness of the triad is part of its beauty.