Just for Piano Society's safety I would put a disclaimer by the recording for US-based listeners. I believe that copyrights are in effect for a certain amount of years after the artist's death. Though I could be wrong.
A disclaimer like:
"By downloading and listening to this recording you are fully aware of your country's copyright laws and by downloading this recording you are fully entitled to obey the laws where present and by no means is the PianoSociety website or adminstrators liable for your acts. "
Nice idea, and good that you are thinking along with us. However:
This assumes the improbable scenario that the law would descend on some poor downloading soder, that person pointing to us as the source of trouble, and then us blithely saying "Hey, we're not responsible, we warned him !" and walking away smelling like roses.
Should copyright become a legal issue at all, it is the hosting site who takes the blame, not the people who download it. Those are impossible to trace and can't anyway be expected to be aware of laws like this. Everything that can be downloaded, will be.