Silence is intellectual property. John Cage’s 4’33”, a lengthy silent track on one of his avant-garde albums, constitutes an original work for copyright purposes. This means that other composers who include silent tracks have made a derivative work from Cage’s silence. Cage’s representatives have served producer Mike Batt with a legal nastygram asserting that he infringed on Cage’s copyright with his 60-second silent track on the latest Planets album.