Wo Gott der Herr nicht bei uns hält

Neumeister's transcription of Bach's prelude to "Wo Gott der Herr nicht bei uns hält" contains surprisingly few errors. Perhaps because it is a piece with just three parts? Bach wrote a nice piece, with the chorale melody in the soprano voice. The accompanying two voices start of with the first phrase of the chorale melody, after that they have little relation with the melody.

Score available here: http://partitura.org/index.php/johann-michael-bach-wo-gott-der-herr-nicht-bei-uns-halt