Manuscript Becker III.8.51, owned by the Universitätsbibliothek Leipzig, contains four fugues for organ or keyboard, from Friedrich Wilhelm Marpurg. They were copied from an unknown source by one J.A. Dröbs (if I read the insciption correctly). This Dröbs was not a very reliable scribe, as there are several obvious mistakes in the manuscript that is additionally often very difficult to read. The scores of these four fugues contain here and there some gueswork of what was actually meant and probably deviate in certain spots from Marpurg's original. As long as I do not have another source for these fugues however, this is for now the best I can do.
The last of these fugues is a fugue in again a minor. Where the other two fugues in a minor from Marpurg I already published (a our part one and a five part one) are rather solid pieces that need a plenum registration to play (at least to my ears) this fourth fugue is of a much lighter character. It has a nice chromatic theme, that Marpurg develops very nicely. Even though the bass voice goes quite high in this fugue (it reaches the e in the one-lined octave) the manuscript specifically indicates it should be played with the pedals. So, again, I rendered this fugue as a three staves score.
The recording was done with the Hauptwerk software and the sampleset, made by Sonus Paradisi, of the Janke organ in the Stadtkirche of Bückeburg (https://www.sonusparadisi.cz/en/organs/germany/buckeburg-janke-organ.html).
Score available here: http://partitura.org/index.php/friedrich-wilhelm-marpurg-fuga-in-a-moll-a-3