No, I am not talking about aura at all, I'm just saying that the physical, measurable sound that an instrument produces in response to being played, physically and measurably, could have more subtle effects on artistic performance (as a consequence of the physical vibrations of the object and the way those vibrations respond to the player and vice versa) than those that could be elided in an afternoon of A/B-testing under the banner of "stradivarius myth DEBUNKED".