frogman,
Of course, the ideal would be comparing live performance of non-amplified music with whatever we have at home. I was mentioning rock'n'roll because it seems to me that most of the members here (Audiogon, not necessarily only this thread) lean towards electrified performances.
At some point, I recorded a piano. As simple as simple gets, no fancy recording equipment, technique, or conditions. Portable MiniDisc with a microphone (around $70-100, I forgot details) in the room. It was surprising how close that recording actually came to the live piano on a relatively, for Audiogon, modest system. Maybe the secret was that both were in the same room, much smaller than any venue one usually listens to piano at. Our regular recordings are, as millercarbon pointed out, processed to resemble what many people along the way wanted them to resemble. Not always the faithful recreation of the event. Recordings bear some room imprint and attempting to recreate that in a living room may make things more complicated.