Ich lasse dich nicht, BWV 1164

Such a mixture of scripture and chorale texts was common for motets of the generation before Johann Sebastian, as also its eight-part setting.

In the second half of the 18th century, Johann Sebastian's son Carl Philipp Emanuel, apparently not assigning the composition to any specific member of the Bach family, joined the early manuscript of its first movement to the Altbachisches Archiv (old-Bachian archive, ABA), a collection of mostly 17th-century compositions by his ancestors.

Containing several motets by Johann Christoph, Max Schneider's 1935 edition of the ABA pieces did not include Ich lasse dich nicht.

[3][2] In the Bach-Ausgabe, the editor Franz Wüllner described the piece as "one of the most beautiful works of German church music" but not "authentic", therefore giving Johann Christoph Bach as the composer.

[3] When Wolfgang Schmieder created the Bach-Werke-Verzeichnis in 1950, he followed Wüllner, placing the motet in the appendix and assigning "presumably by Johann Christoph Bach".

We cannot be totally sure, but from the evidence of the way the score is presented it suggests this was indeed composed by Bach, in which case it is the earliest surviving motet of his, dating from c. 1712/13, or possibly earlier, when he was employed at the Ducal court in Weimar.

In terms of style it gives the impression of occupying a mid way point between that of Johann Christoph Bach and, say, Fürchte dich nicht.

The motet for double choir is followed by the third stanza of the hymn "Warum betrübst du dich, mein Herz" by Erasmus Alberus.

[4][2] In the second section, the choir is no longer divided, the soprano sings the cantus firmus of the chorale, while the lower voices engage in imitative polyphony.

[6] The added chorale in the same key is the eighth stanza from "Warum betrübst du dich, mein Herz", Dir, Jesu, Gottes Sohn, sei Preis", set for four parts.