The first two parts of the work are the only ones which need special notice for the purposes of the oratorio-goer. The first part opens with a brilliant prelude, introduced by the drum, which Bach, like Beethoven, sometimes treated as a solo instrument. It preludes the narrative bidding Zion prepare to meet her Lord,--a simple, touching melody, followed by the chorale, "How shall I fitly meet Thee and give Thee welcome due," set to the old passion-hymn, "O Haupt, voll Blut und Wunden,"--a solemn and even mournful melody, which at first appears incongruous in the midst of so much jubilation. It is the same melody which Bach frequently uses in different harmonic forms in his "St. Matthew Passion." It is introduced here in the midst of the Christmas festivity for a special purpose. Bitter gives it the following significance:--
"We see the Angel of Death unveil his pale face, bend over the cradle of the Lord, and foretell his sorrows. The Child hears the song which one day, sung to other words, will be his death-song."
The composer's evident intention was to impress the hearer with the fact that the object of the divine advent on earth was the passion of our Lord. At the close of the work the same chorale appears, but it has another meaning. It is there an exultant expression of Christ's victory over sin and death. As the chorale dies away, the narrative is resumed, leading up to another chorale, "For us to earth he cometh poor," combined with an orchestral symphony and bass recitative. The next number is a bass aria with trumpet accompaniment, "Lord Almighty, King all glorious," and is followed by a chorale set to the words of Martin Luther's Christmas hymn, which also occurs in other parts of the work, differently harmonized to suit the nature of the situation, with which the first part closes.
The second part opens with one of the most delightful instances of Bach's orchestration, a pastoral symphony, with which the Thomas orchestra have made audiences familiar in this country. Like the symphony of the same style in Handel's "Messiah," it is simple, graceful, and idyllic in character, and pictures the shepherds watching their flocks by night on the plains of Bethlehem. At its conclusion the evangelist resumes his narrative, followed by the chorale: "Break forth, O beauteous, heavenly Light," preluding the announcement of the angel, "Behold, I bring you Good Tidings." It is followed by the bass recitative, "What God to Abraham revealed, He to the Shepherds doth accord to see fulfilled," and a brilliant aria for tenor, "Haste, ye Shepherds, haste to meet Him." The evangelist gives them the sign, followed by the chorale which closed the first part, in another form, "Within yon Gloomy Manger lies." The bass recitative, "O haste ye then," preludes the exquisite cradle-song for alto, "Sleep, my Beloved, and take Thy Repose,"--a number which can hardly be excelled in the sweetness and purity of its melody or in the exquisiteness of its instrumentation. This lovely song brings us to the close, which is an exultant shout from the multitude of the heavenly host, singing, "Glory to God in the highest."