Sorge's prelude to "Nun lasst uns gehen" follows the pattern of the preceding ones: one manual for the accompaniment and one manual for the choral melody. Interesting in this piece is that the choral melody is presented in the accompanying voices before it appears on the solo manual. The accompaniment can best be presented using the alto clef. Sorge however does not use it in the manuscript. As a consequence, the lower voice of the accompaniment is sometimes written on the pedal staff, while the upper voice is written on the middle staff, using the g-cleff. I decided to follow Sorge's way of writing as the alto-clef is difficult to read for most people.
Score available here: http://partitura.org/index.php/georg-andreas-sorge-nun-lasst-un-gehen