The second cantata of the Christmas Oratorio decidedly changes character to focus on the shepherds. It is the only cantata in the Oratorio that opens with an instrumental Sinfonia, including pairs of flutes, oboes d’amore, and oboes da caccia, in siciliana form, typically associated with bucolic and pastoral scenes. The same sonority is presented in the final chorale, reaffirming this framework for the entire cantata. The juxtaposition of flutes and oboes can be interpreted the dialog between the divine (angels) and the earthly (shepherds) narrated in the text.
At the end of the symphony, the Evangelist advances the narrative, recounting the appearance of the angel to the shepherds who were taking care of their flock at night. A chorale, taken from a hymn by Johann Rist of 1641, provides an opportunity for the congregation to reflect on the significance of the birth, and then the Evangelist resumes his speech, now in an “accompagnato” with strings, to introduce the angel, represented by the soprano soloist.
After the angel’s announcement, the bass delivers another “accompagnato” recitative, pointing out that the shepherds are the first to receive the news and testify to God’s ancient promise. The accompanying instruments are now the four oboes, a musical reference to the shepherds. The recitative leads to a tenor aria, sourced from BWV 214/5, which in its second section illustrates with agile passages the words “Geht”, “Freude” and “labet” (“go”, “joy”, “comfort”). The original piece was for alto with 2 oboes in unison. Bach transposed it up a fourth, substituted a flute for the oboes and gave it to the tenor.
The Evangelist continues the story, noting that the Child will be found in a manger. This text, even though it’s assigned to the Evangelist in the libretto, is actually the final line of the angel’s announcement. It’s followed by another chorale, mid-point of the cantata, which provides a moment of reflection on the image of the Child in the manger. The chorale text is by Paul Gerhardt, of 1667.
The bass, again in a recitative accompanied by the oboes, personifies the listener and exhorts the shepherds to go in search of the Son of God. The second section of the recitative suggests the image of the crib, or the action of cradling, with rocking sextuplets on the continuo line.
Next, the alto, impersonating Mary, sings a delicate lullaby with the oboes doubling the strings and the flute at the octave with the voice, providing a particular glowing effect. This aria, sourced from BWV 213/3, is a good example showing how Bach makes adjustments to suit the new context – in this case, adding the flute and the oboes, in addition to performing the necessary transposition to change the voice from soprano to alto.
The Evangelist then comes back to announce the appearance of the “heavenly hosts” in praise, which leads to an extensive choral fantasia that illustrates, with three well-differentiated motifs, the concepts of glory to God, peace on Earth, and good fortune for humanity. This chorus is, as far as we know, original music composed specifically for the Oratorio.
The bass reappears as a representative of the congregation, this time addressing the angels, proclaiming the intention of humankind to join the angels in celebration. This leads to the closing chorale, again on a verse by Paul Gerhardt, which reinforces the concept of general rejoicing. The orchestra contributes quotations from the opening sinfonia between the chorale lines, lending unity to the pastoral mood of the cantata.
