Komm heiliger Geist, Herre Gott (alio modo)

Sorge's second chorale prelude to "Komm heiuliger Geist, Herre Gott" from manuscript Mus Ms 30376 (Staatsbibliothek Berlin) shows him from another side. No trio like texture, but a four voice fugue, with the first phrase of the chorale melody as fugue theme. Sorge is not the greatest writer of fugues. If it were written for an exam, he would barely pass it, I think. The chorale theme, however is easily recognizable in all it's 9 appearances. It's a bit strange than that the theme doesn't appear in the last 7 bars (almost a quarter of the total length of the piece).

Edit: it's not a fugue at all. See AAHunt's comment. I guess it's me who would really fail an exam... :-)

Score available here: http://partitura.org/index.php/georg-andreas-sorge-komm-heiliger-geist-herre-gott-alio-modo