Available information:
https://www.oberlin.edu/blogs/my-piano-weekend-experience
https://www2.oberlin.edu/alummag/oamcurrent/oam_fall98/around/schwartz.html
https://www.tampabay.com/features/humaninterest/though-life-gives-and-takes-85-year-old-piano-phenom-never-loses-control/2321967/
https://www.nytimes.com/1964/12/28/archives/joseph-schwartz-in-piano-program.html
https://www.youtube.com/watch?v=tQRf8tR51GY