@HogTime ... I love a good discussion ... even when I'm blowin' smoke!

I'm going with 'Occam's Razor' ... the simplest explanation that could fit the facts.

Why would you take a midi auto arranging program's files (which I'm pretty sure are only 'proprietary' midi with a diffent file extension and a few other tricks), convert that to some new code to compile audio from a virtual sampler (which is what RT is) and then develop some more new code now to compile midi data for charts in RT?

Wouldn't it be a lot simpler to use the same 'front end' midi data and then only trigger your virtual sampler 'compiler' with it?

But! You may be right.

Prado