The work opens with an extended sinfonia, making for a formal introductory movement that compensates well for the reduced number of vocalists. For this setting, Bach revises an earlier concerto movement for an unknown solo instrument; a reworking which together with the fifth movement of this cantata, found its way at the end of the 1730s into the E Major Concerto for Harpsichord and Orchestra (BWV 1053). The solo part, assigned to the organ in the cantata, appears to have been played directly from the score, indicating that Bach – a virtuoso organist – may well have played the part himself.
Following the expansive introductory movement, the arioso commences with an extended continuo ritornello that provides a relaxed framework for the cantabile motto “God all alone my heart shall master”, a head motive that is interspersed with figurative recitatives. In aria no. 3 the librettist and composer embark on a risky venture, beginning as they do with the already oft-recurring motto. In the new musical setting, however, Bach combines a striding bass with a nervous, almost jazzlike syncopated organ part that stands in stark juxtaposition to the hymn-like quality of the vocal lines. Compared to the highly contrasting soliloquy of the preceding arioso, this aria seems to exude open acceptance of the biblical word as the foundation of life’s truth.
Despite its brevity, the alto recitative no. 4 proves to be a rich collage of images and attributes expressing God’s love and its import for human existence. Here, the text is rich in allusion to the wonder of the Passion, referring to both the bosom of Abraham and Elijah’s chariot. The following aria “Die in me, world!” resumes this sentiment with a mesmerising siciliano form and the “have mercy!” tonality of B minor. In this movement, the intensity of the interplay between the various parts stands in such bold contrast to the libretto’s plain condemnation of worldly desires that it would not be entirely surprising to learn the music stemmed from an earlier source. Either way, the later reworking of this movement as the middle section of the Harpsichord Concerto in E Major is a potent reminder of the great effort and sensitivity with which Bach approached his parody compositions.
The following recitative abruptly draws our attention from the quixotic reflections of “religious specialists” to the earthly necessity of loving one another in the here and now. Here, the text’s somewhat dry reference to Christ’s directive exposes a weakness of Lutheran ethic: where do we find the motivation to love our neighbour if deeds of compassion are no longer necessary for salvation? The closing chorale provides a moving answer to this dilemma by singing in vibrant A major of the fervent “tenderness” that is inherent to a life of fellowship and goodness of heart. In this setting, Bach musically transforms the concept of virtue into an experience of the senses, while its identity as a Kyrie lends both choral movement and text liturgical import.