Here's my info:
"The singing with the piano tuned in Just Intonation is amazing! The voice fits into the resonance of the piano when it is in Just Intonation as if the overtones are sound structures and there is room for the voice. I feel and see the overtones play with each other but not fight for space.
As a recording engineer I would have had to lower the volume of the piano (a typically tuned piano in equal temperament) in order to make space for the voice. This is very common in mixing music.. You lower the volume to make space for instruments of similar frequencies. However when the piano is tuned in Just Intonation there seems to be no competition for space between the piano resonance and the voice even when they are in the same range... They do not compete. The sonic structure of the Justly tuned piano has space for the voice.
As a singer this is incredibly fun! And I no longer have to push the voice or make it a more pointed sound to get over the piano... Now there is space and this allows me to use any vocal tone I want or need for the phrases or lyrics... Even softly sung vocals are easily heard within the piano resonance. I wish I could draw it... maybe an oscilloscope would show what is going on with the overtones."