Bach Cantata BWV 12 is his first setting of a Salomo Franck text. Franck was the greatest librettist that Bach ever worked with, and this cantata has a marvelous sense of discovery about it. It opens with a poignant sinfonia for oboe and strings, setting the mood and character for the moving opening chorus. The extreme expressivity of the choral parts is counteracted by the rigor of the chaconne bass. Thirty years after the composition of this cantata Bach remembered this chorus and arranged it as the Crucifixus in the Mass in B Minor.
The only recitative in this cantata is not free verse but a quote from the bible reading for Jublilate Sunday. It is set for alto and strings. The great aria that follows for oboe and alto solo is Bach’s first extended oboe solo and thus the beginning of a remarkable body of work. The text for the bass aria uses the metaphor of “following” to color the whole structure. The two solo violins dutifully follow both the bass and each other. The tenor aria, a mournful and expressive plaint, is accompanied by the chorale melody, “Jesu meine Freude” on the oboe. “Was Gott tut, daß ist wohlgetan” ends the cantata in a harmonization with the violin above the sopranos providing a fifth voice.