Fuga g moll

Manuscript Am B 340 contains two fugues, that have the initials "F.S" written beneath the title. Presumably those are the initials of the original composer of this fugue. Alas, I have no idea who these initials belong to. The fugue itself is beautifully crafted. The exposition is very short, as the theme enters pairwise in the four voices. In each pair the second statement of the theme starts halfway the first statement. After that the fugue flows calmly along the lines set out by the theme, elegantly and enjoyable. So, if someone has an idea as to whom might be the composer of this piece, I'd very much like to know it.


Score available here: http://partitura.org/index.php/wilhelm-karges-f-s-fuga/