In the opening chorus, "Christ unser Herr zum Jordan kam" (Christ our Lord came to the Jordan), the tenor has the melody as a cantus firmus, while the other voices sing free counterpoint.
In the first cantata of the chorale cantata cycle, O Ewigkeit, du Donnerwort, BWV 20, Bach had given the cantus firmus of the chorale tune to the soprano, and in the second, Ach Gott, vom Himmel sieh darein, BWV 2, to the alto.

The opening chorus resembles an Italian violin concerto.
The musicologist Julian Mincham likens the "solo violin's persistent, rocking, wave-like idea" to the waves of the Jordan River.
Alfred Dürr compares the vocal sections, all with the solo violin, to the solo sections of a violin concerto, as opposed to the tutti sections with the orchestra.
John Eliot Gardiner interprets the movement as a French overture, "replete with grandiloquent baroque gestures to suggest both the processional
entrance of Jesus and the powerful flooding of the River Jordan".
Klaus Hofmann notes that the movement combines the old style of motet writing with the new type of solo concerto, and observes that "the main violin solo episodes ... are at first linked to the choral entries, but gradually assume larger proportions and greater independence as the movement progresses".
In the opening chorus, "Christ unser Herr zum Jordan kam" (Christ our Lord came to the Jordan), the tenor has the melody as a cantus firmus, while the other voices sing free counterpoint. In the first cantata of the chorale cantata cycle, O Ewigkeit, du Donnerwort, BWV 20, Bach had given the cantus firmus of the chorale tune to the soprano, and in the second, Ach Gott, vom Himmel sieh darein, BWV 2, to the alto.
The opening chorus resembles an Italian violin concerto. The musicologist Julian Mincham likens the "solo violin's persistent, rocking, wave-like idea" to the waves of the Jordan River. Alfred Dürr compares the vocal sections, all with the solo violin, to the solo sections of a violin concerto, as opposed to the tutti sections with the orchestra. John Eliot Gardiner interprets the movement as a French overture, "replete with grandiloquent baroque gestures to suggest both the processional
entrance of Jesus and the powerful flooding of the River Jordan". Klaus Hofmann notes that the movement combines the old style of motet writing with the new type of solo concerto, and observes that "the main violin solo episodes ... are at first linked to the choral entries, but gradually assume larger proportions and greater independence as the movement progresses".
Christ unser Herr zum Jordan kam, BWV 7