Johann Samuel Harsow (~1759 – 1792) was organist of the St. Marienkirche in Berlin. He was a pupil of Johann Philipp Kirnberger, and was during his short life acclaimed as an outstanding performer of Bach’s organ works. Harsow composed a number of chorale preludes in trio and bicinium style.
I found an very early edition (around 1790) of two of them. The music is not very high quality, so I post them both at once. “Lobt Gott, ihr Christen allzugleich” is the first.