Cantata 40 was composed for the second day of Christmas of 1723. It was first performed on December 26th of that year, and we have records of a second performance in the late 1740’s.
Its libretto, by an unknown poet, makes little reference to readings of the day (although it includes several biblical references), instead focusing on describing Jesus as the destroyer of sin. Like other cantatas of this period, the first movement is a “dictum” – i.e. a literal passage from the Bible, in this case the First Epistle of John, chapter 3 verse 8. The libretto also incorporates three chorales, two of which are Christmas hymns (movements 3 and 8) and one selected strictly based on the content of the verse (movement 6).
Thematically, the libretto can be thought of as divided into three sections, each finalizing with a chorale. Movements 1-3 discuss Jesus coming into the world to destroy sin and bring joy, comfort, consolation and salvation. Movements 4-6 introduce the image of the serpent and portrays Jesus as its “crusher”. Movements 7 and 8 are a song of joy.
The cantata is orchestrated for 2 French horns, 2 oboes, strings, continuo, four-part choir and three vocal soloists (alto, tenor and bass). It opens with a joyful, large scale chorale movement to which the inclusion of the horns, most likely a surprise for Leipzig congregations, lend a joyful character. Bach reused this movement later as the “Cum Sancto Spiritu” of the Lutheran Mass BWV 233. The initial material is marked by the horn calls, interplaying with the oboes and strings, and a largely homophonic rendering of the text by the choir. The middle section is a fugue in which the theme is taken in succession by each of the voices, with a busy countersubject in sixteenths, as a melisma suggesting a serpent on the word “zerstöre” (“destroy”).
The tenor then gets an expressive secco recitative, including word painting on “bestrahlt” (illuminates) as an upward run of sixteenths, imitated by the basso continuo. An octave-wide descending motif in eighths illustrates Jesus becoming a human child.
The first chorale closes this initial section of the cantata. It’s set in four parts, with the instruments doubling the voices. The bass line uses raising chromaticism for emphasis of the rhetorical question posed in the last verse: “Who can condemn us as Christians?”
Movement 4 starts the section of the cantata that deals with the image of the serpent. It opens with a combative, dramatic bass aria of triumphant character and even with hints of a dance, due to its 3/8 dotted rhythm and periodic phrasing. Bach injects high energy into the texture via a continuously moving line of sixteenth notes in the first violins, occasionally taken over by the basso continuo. The action of crushing the serpent’s head is suggested in wide descending leaps throughout the musical material.
After the agitation and bravura of the bass aria, the alto takes over with a sweet accompagnato recitative. The strings weave a sustaining texture with constant arpeggios, as the text narrates how Jesus takes away the danger and poison of the snake.
The second chorale, obviously selected by the librettist for its references to the snake, is again presented in plain four-part harmonization. Given its text, some performers choose to give it an extra edge by using shorter articulations and a more agile tempo.
The last two movements focus on the believer rejoicing upon the coming of Jesus. The tenor aria is festive and dance-like in its ternary rhythm, accompanied by the horns and oboes, without strings. It features extraordinarily long melismas on “freuet” (“rejoice”), which make it one of the technically hardest arias in the tenor repertoire. “Höllenreich” (“rage of hell”) is illustrated with chords from the horns on repeated notes, and “erschrecken” (“frighten”) by rests that interrupt the music mid-word.
The closing chorale, set in four-part harmony, reads like a prayer for peace and blessings in the new year and a reaffirmation of the congregation’s joy.
