How does solo piano help you evaluate audio gear?

You cannot have a piano right and violin wrong AT THE END...

You cannot have all these two right and voice wrong AT THE END of the process...

First voice... Because we are inwardly tuned to recognize voices...

Then piano...Because of the huge dynamical field covered by this instrument...

Then violins and brass and wood...Or orchestra... Because the great number of this different timbre playing together distinctly is great test to end...

There is an order for me because i use that to test my room for the tuning for months...

IMO, the problem with using a piano as a reference (generally) is that there are so many poorly recorded piano pieces. The piano must/has to be the hardest instrument to get recorded correctly to fully reproduce its the broad and nuanced (detail) sound capabilities, much more apparent live.

Very true...

I used Moravec nocturnes Chopin or Feltsman Bach Well tempered Klavier....Only these 2...They are very different but good in their own way...The Moravec recording though is unsurpassed both musically and sonically...But the dynamic of the Feltsman recording is sometimes stunning for bass notes tuning ...

In an incremental process of tuning the room for months you must know the recording very well and it must be a good one....

IMO, the problem with using a piano as a reference (generally) is that there are so many poorly recorded piano pieces. The piano must/has to be the hardest instrument to get recorded correctly to fully reproduce its the broad and nuanced (detail) sound capabilities, much more apparent live.

You must be able to recognize these three very different timbre: