Kauffmann's prelude to "Schmücke dich, o liebe Seele" has the choral melody in the upper voice. The other two voices are never far apart and can be played with one hand. It is therefore possible to play the choral melody with the right hand and play the accompaniment with the left hand on another manual.
The recording was done with the Hauptwerk software and the sampleset, made by Voxus, of the Müller organ in the Sint Bavokerk, Haarlem (http://www.voxusorgans.com/en/product/haarlem).
Score available here: http://partitura.org/index.php/georg-friedrich-kauffmann-schmucke-dich-o-liebe-seele