I think that this subject is a particularly interesting one, in the context of
many of the ideas that have been promoted in previous threads about how
we listen to music.
I have always had trouble with the idea that any one particular musical
instrument can, and should, be used as a litmus test in judging the possible
ultimate "accuracy" of record/playback equipment. To do so is
to not understand the subtle tonal variety and shadings that other musical
instruments exibit. Additionally, an instrument that is truly capable of going
from pppp to ffff is no guarantee that it will convey accuracy from p to pp;
and everything in between. Not to mention, the tonal stuff.
In the case of the piano: Sure, the piano can sound at a volume and
frequency range that an oboe can't, but the oboe's sound posseses tonal
shadings that the piano's does not. The wide variety in tonal signatures
between oboes (and most other wind and string instruments) is far greater
than anything that I have ever heard from different pianos. Of course, it's
great to be able to pick out the Steinway from the Yamaha, but ten clarinet
players, all playing the same brand clarinet, will each sound uniquely
different.
So, the question has to be asked: what is it that we are listening for? This
comment is not meant to criticize, nor invalidate, how a given listener
priotizes sonic benchmarks; but, in my opinion, to go in that direction of
priorityzation can pull the listener away from the notion of listening for true
accuracy in musicality.
If the analysis of recorded music accuracy (litmus test?) is to have any real
relevance, then how MUSIC (not just sound) is analyzed and discussed
has to be part of the mix. In music, no instrument is deserving of more
respect than any other; in spite of all the viola jokes. Having said all that, a
favorite piano recording with fantastic playing: Murray Perahia "The
Aldeburgh Recital".