His amanuensis, if you will, was composer Jack Gottlieb.  

I met Leonard Bernstein twice, first at the Madison Avenue Bookstore signing his Unanswered Question (I gave him a copy of my Hasty Recovery Score and he signed the original of the score.) and a second time at that uptown theatre near the former Thalia oh you know what it's called (Symphony Space)... at Peter Maxwell Davies's "Fires of London" band performance of Vesalii Icones.