Exactly, you have only performed Cage's work if you set out with the intent to play Cage's work. This obviously makes it impossible to determine if a particular

Exactly, you have only performed Cage's work if you set out with the intent to play Cage's work. This obviously makes it impossible to determine if a particular performance of silence is a performance of Cage's work without reading someone's mind, but that same issue of determining intent comes up a lot in legal matters.