Differnt issue. 4'33 is a recording of the audience, not silence. I studied it in a music class in school. Cage's estate's infringement claim on "silence" was

Differnt issue. 4'33 is a recording of the audience, not silence. I studied it in a music class in school. Cage's estate's infringement claim on "silence" was not upheld by a court. The defendant on that suit put Cage's name on the album as a songwriter, of his own accord.