This book presents one of the most innovative artists of the 20th century, John Cage. It includes the installation Essay which, inspired by Henry David Thoreau's The Duty of Civil Disobedience, was designed by Cage for Documenta 8 in Kassel. Also featured is the music presented at the John Cage Music Festival. This Festival presented works composed by the artist throughout his career and was attended by many of the performers for whom Cage originally composed.