how would you describe a system that is musical in nature

A musical system has a certain magical quality that happens in your brain when you hear it. Some say it makes you turn your head to the sound. I do not think it is easily defined. As the supreme court justice once famously stated "I know it when I see it" . Change see to hear.

A musical system is one you enjoy listening to.

If you need further clarification on "how will I know my system is musical," look up Justice Potter Stewart's description of pornography

Visit a local piano store. Listen to a customer playing.  From different distances - 5ft to 50 ft.

Attend a live acoustic music venue:
- a small club
- a medium-sized recital hall
- a large concert hall

Another example like the piano store...
I walk down the street and my neighbor's kid practices his trumpet in his house. I hear him struggle through scales and a classical piece I can't even identify. He skills are those of a beginner. But I immediately know it's live music being played, even outside the house. 

The excellent descriptions above about transparency, resolution, and micro dynamics get to the heart of reproducing that connectivity in your musical system. Cheers,
Spencer

Every piano I ever seen is locked up so no one can play it. Something to do with chopsticks I am told, whatever that is.