Yesterday I published the first of two preludes to "Christ lag in Todesbanden", contained in manuscript Mus ms 40037, owned by the Staatsbibliothek Berlin. The first of these is acribed to Zachow in the manuscript. The second does not have an indication of the composer.
In 1966 Heinz Lohmann published his collection composition by Friedrich Wilhelm Zachow. In this edition he provides a catalogue of Zachow compositions as well. This catalogue is still in use today and is generally called the "Lohmann Verzeichnis", or in short LV. Lohmann catalogued both preludes as number 47, probably presuming both works belong together and were both composed by Zachow. Based on the style of composition, or perhaps better, the quality of the composition there is reason to doubt the authorship of Zachow. The fact that in Mus. ms. 40037 this composition is not attributed to Zachow lends further reason for doubt. Both preludes are therefore considered seperate works, hence the original Lohman number 47 is split in LV 47(a) and 47(b).
In this prelude the choral melody is played with the pedals, while the upper two voices play an accompaniment based on motives from the choral melody. It is far from a badly written composition. It is just not as good as you might aspect from Zachow.