The 17th fugue of Lohet is a mono thematic fugue and an intricate one. In it Lohet explores the different ways in which the theme and its inversion can be combined. The theme overlaps in different ways with itself, with its inversion and the inversion with the inversion.
The fugue shows frequent voice crossings. Voice crossings are very easy to notate in German organ tabulature. In our modern notation voice crossings quickly become messy. In the score I let the voices cross the staves, indicated by small lines. That way the individual voices can still be followed, but the score is more easily playable.