So I'm guessing this isn't possib;le:

IIt can be done in software but I thought it would be really cool to do it in a modular system.

So maybe I have to take a step back.

Are there any modules that can make a 'musical' decision?

I can expand on that - and will if requested :-) - but I thought I'd leave it open to see what, if any, suggestions there are.

I'm interested in ways a modular can 'react' to current pitches/CVs rather than running a S&H through an attenuator and quantiser.