Complex sentence: The soloist introduces a new wording'(Forget them not, the dead), repeated by the chorus (espressivo, dolcissimo) on the melody of the chorale', five stanzas of which Bach used in his "St Matthew Passion".
Split into simpler sentences: The soloist introduces a new wording'(Forget them not, the dead). The chorus repeats this phrase, marked espressivo, dolcissimo, on the melody of the chorale', five stanzas of which Bach used in his "St Matthew Passion".