With live acoustic music as a reference, we can, over time, get to a place where we have an idea
of which recordings and components or systems seem to come closest to this ideal.
If we persist, over time we will make progress toward that ideal. I think that's what drives me in this hobby, at any rate.
(As an aside, the apparent lack of the industry doing this, to his eye,
is what seems to have driven JGH to madness.)
I think Alex's point about there being no prefect "knowable" reference
for any given recording is true.
It's just that I don't think that perfectly reproducing one specific
recording is the goal of Hi Fi. I want my system to come as close as possible to doing this for as many recordings
as possible (if that makes sense.)
I think Alex is painting with too narrow a brush, but he's right about any single recording.