Kauffmann's prelude to ``Es spricht der unweisen Mund wohl'' is written for two manuals and pedal. It is however not immediately clear which part should be played with the (left) hand and which part with the feet. If the bass part is meant for the feet it is of enormous difficulty, unparalleled in Kauffmann's music. And the part goes up to e2, hardly ever available on pedal boards in Kauffmann's time. It seems more logical to play the chorale melody with the feet, however, there is no indication in the source that it is meant as such. And the chorale part goes up to e2 as well. Of course, with a suitable registration it can be played an octave lower. And that's another question: should the chorale melody be played as written? Or registered with a 4' stop? The performance plays the chorale melody with feet and a 4' stop. I provide a score with the bass in the pedals as well, for the true virtuoso among us. Even with the choral melody in the pedals, it is not an easy piece. Kauffmann employs a concertante style that suggests that this piece was originally written for an instrumental ensemble. Or he just liked the effect it gives on an organ.