This is one of the oldest traditional Christmas carols. The composer is unknown but there are records of it being sung within the Christian Church as far back as the 15th century. In 1843 Charles Dickens included the song in his famous novel A Christmas Carol. This arrangement is in classical style with choir, harp, flute, and strings and imparts a sound much like it might have been performed in a medieval cathedral at mass in the middle ages. Reverent and respectful.