"Hark the Herald Angels Sing" was one of the many hymns written by Charles Wesley. It was sung to various tunes but never widely loved. Then a young opera singer was singing Mendelssohn's opera The Festgesang and thought the chorus fit the hymn. Immediately it became popular, but the words would have been lost long before if not for a printer who needed to fill a blank space and printed the words. The lesson is obvious—Christmas fills a blank space on the calendar, in the home, in the church and in our hearts.