We knew he loved books and reading, now we know he must have loved the visual arts as well, since I doubt Knobelsdorff would have left his collection to an ignoramus who just uses it to impress people.

I just turned up something in the inventory of his rooms in Wesel in 1730:

eine süßklingende Flöte („Flothe douce“)
eine Querflöte („Flothe Traversière“)

So two flutes! Being an 18th century nobleman, Peter having an instrument doesn't surprise me, and being a boyfriend of Fritz, it being a flute doesn't surprise me. Since we have no mention of him and music later, either his interest didn't make it into our admittedly very limited sources on him (e.g. the visual arts have *just* turned up), or, as I speculatively put in my fic, he tried out music but was never talented (or merely passionate, as Fritz was about poetry) enough to become notably good at it. (Look, I want *one* of these characters to not be passionate and/or talented when it comes to music so I can relate, okay? :P Yes, Ulrike, but I haven't written fic about her.)

But man, I need to go study German so I can read Kloosterhuis beginning to end someday. I know there are all sorts of things in there waiting for me.