“On the road between Rochester in New York State and Philadelphia, [John] Cage prepared Diary: Audience 1966 for a presentation in New York in May. With characteristic self-discipline, he ascertained at the start of each leg of the journey how many words were needed for the next statement of the text, formulated it and revised it in his head as he drove, pulled over and wrote it down, checked the length of the next statement and drove on. By the time he reached Philadelphia, the piece was finished.” 

David Revill, The Roaring Silence, John Cage: A Life, New York: Arcade Publishing 1992, p 215