In his prelude to "Schmücke dich, o liebe Seele" Marpurg uses the same procedure as in het preludes to "Was Gott thut das ist wohlgetan", "Von Gott will ich nicht lassen" and "Aus tiefer Noth schrei ich zu dir". The composition has a simple 3 part text, with the choral melody in the upper voice. The left hand plays the accompaniment, which not much more than elaborate the notes of the chord that the bass line indicates.
The left hand part in this composition is quite elaborated, probably as a way the express the "schmücke dich" (adorn yourself) of the title of the choral. Though perhaps not very original an idea (Bach did something similar in BWV 654, by using lots of trills in the accompaniment), it is nevertheless executed skillfully.