Manuscript Mus ms 40037, owned by the Staatsbibliothek Berlin, contains 5 chorale preludes to "Jesus Christus, under Heiland, der von uns". At least three of them were composed by Zachow. The one designated as LV 7 in the Lohman catalogue is a fugato based on the first phrase of the choral melody and a counter subject. Each of the four voices plays the choral phrase twice. It's a nice solfeggio to try and spot them all without looking in the score.