Kauffmann's prelude to "Jesus Christus unser Heiland" is a magnificent Trio. The first phrase of the choral melody is combined with a chromatic descending line, written in double counterpoint to the choral melody. Both subjects appear throughout the piece in all three voices. It effectively depicts the suffering of Christ of which the text of the first stanza of this choral speaks. It's a beautiful and evocative piece, one of the best of Kauffmann I have come to know.
The new sample set of Piotr Gabrowsky is really good. The pedal is a bit too much perhaps for softer pieces, but that's probably how it is on the real organ. The recording is nice and clear and the reverberation gives depth to the sound without blurring it. Good for practice ánd performance.