The Ieaskul F. Mobenthey modules are wonderful … I have the whole set and they are quite a lot of fun. Denum, Swoop and Fourses are based on a concept Peter Blasser calls bounds/bounce oscillation. Where bounds represent the upper and lower bound of the oscillation (amplitude) and bounce is the rate (frequency). The trick here is that the bounds and the frequency are interconnected, meaning, if the bound is getting “shorter” (distance between upper and lower bound) the frequency is going up. In case of the Denum (the triangle based “oscillator” in the series) this results in sounds that are a mixture of AM and FM and can get quite complex.
For anybody interessted in Ieaskul F. Mobenthey modules I can recommend watching the videos of John Macedo, CrucFx and Triangle.
And this video by Tim Cosgrove shows how wonderful rich the Denum can sound:
Edit: I would absolutely love a recreation of these in VCV Rack (or at least of the concept of bounds/bounce oscillation)
Edit 2: This here goes into that direction and is very similar to how Fourses works.