There is an amazing composer in Philadelphia by the name of Robert Moran. Years ago, I was introduced to his work via the WNYC show "New Sounds" when they played part of his choral work, "Seven Sounds Unseen". Part of what they are singing are excerpts from letters he received from his dear friend John Cage. The work is stunningly beautiful.
You can buy it here.
He also wrote a p;ice for children's choir for the tenth anniversary of 9-11. It is one of the most beautiful pieces I have ever heard. You can hear him talk about it here.
Much to my joy, Robert and I have been friends for quite a few years and, yes, we have corresponded.