Bach scored the work for four soloists, a four-part choir and a Baroque instrumental ensemble of a cornetto to reinforce the chorale tune, two oboes d'amore, strings and basso continuo.
[2][4][5] It is one of the newest of the chorales which served as a base for the cycle, whereas Bach otherwise preferred the beloved hymns of poets such as Martin Luther and Paul Gerhardt.
Bach scored the work for four vocal soloists (soprano (S), alto (A), tenor (T) and bass (B)), a four-part choir, and a Baroque instrumental ensemble of a cornett (Ct) to double the chorale melody, two oboes d'amore (Oa), two violin parts (Vl), one viola part (Va), and basso continuo.
[7] In the following table of the movements, the scoring, keys and time signatures are taken from Alfred Dürr's standard work Die Kantaten von Johann Sebastian Bach.
In the opening chorale fantasia, "Ich freue mich in dir und heiße dich willkommen" (I rejoice in you and bid you welcome),[1], the cornetto plays the cantus firmus with the soprano, the oboes play in unison with violin II and viola, whereas violin 1 "shines above the rest".
[3] The lower voices are set mostly in homophony, with the exception of expressing "Der große Gottessohn" (the great son of God).
[3] John Eliot Gardiner, who conducted the Bach Cantata Pilgrimage in 2000, summarised: "I find it hard to imagine music that conveys more persuasively the essence, the exuberance and the sheer exhilaration of Christmas than the opening chorus of BWV 133".
Motifs of runs as in the opening still occur in the aria, but it is dominated by a repeated call of the oboes,[12] in "rhythmically accented ascending interval leaps",[4] that the voice sings to the word "Getrost".
[12] The tenor recitative, "Ein Adam mag sich voller Schrecken vor Gottes Angesicht im Paradies verstecken" (An Adam might well, filled with terror, from God's countenance hide himself in paradise),[1] is marked adagio twice for text quoted from the original chorale, once to stress "Der allerhöchste Gotte kehrt selber bei uns ein" (Almighty God Himself here visits us),[1] and the conclusion, "Wird er ein kleines Kind und heißt mein Jesulein" (He has become a little child and is called my little Jesus).
[4] In the middle section the time shifts to a siciliano,[6] the tempo to adagio, and it is unusually played without continuo, just a trio of the soprano, the first violin and the lower strings in unison.
[4] The bass recitative, "Wohlan, des Todes Furcht und Schmerz erwägt nicht mein getröstet Herz."
[12] The cantata is closed by a four-part setting of the last chorale stanza, "Wohlan, so will ich mich an dich, o Jesu, halten" (Indeed, thus I will cling to you, O Jesus).