Sometimes certain songs are played, sung or celebrated only at certain times during the year. Often-times the prettiest of these are saved for the "holidays." For me, that means Christmas, sometimes Thanksgiving, and maybe even New Year's Eve or New Year's Day. Why many of these songs are sequestered into these particular time-spots can appear to be rather logical. Many of them ARE "holiday" songs.
But there are others of these songs... these celebratory or plaintive songs... that can be, may be, or even should be sung all the year through. If only the theme requested, hoped for, or even prayed for by the above song... Let There Be Peace On Earth... could be seen by more than myself... as something to be celebrated all year 'round... how truly wonderful that would be.