I'm wondering the right place to ask this question.
What I'd like to do is to take a simple midi ear training app (with possibly vst~ output) that I wrote years back in Max/MSP 6 (I never bothered to upgrade from 6 given the cost and how little I used it).

You'll might find the cyclone library useful. It clones a bunch of Max objects in Pd. Go to Tools->Find externals and type "cyclone" to get it.