I am so SAD to hear this.
In 1973, I lived down the street from him. At the time, he was living in a renovated barn! I fell instantly in love with his music and followed him/his career in all the years that followed. What an amazing talent he had. Gifted, and utterly willing to share that with others.
So glad I was at Orchestra Hall every day after Christmas for years and years. Really treasured memories.