If you just produced an audio file containing silence and marketed it as a song you would be fine. The only way you would be found infringing is if they could s

If you just produced an audio file containing silence and marketed it as a song you would be fine. The only way you would be found infringing is if they could somehow prove that you copied Cage's silence (or produced your silence using the "score" to Cage's silence) instead of independently composing and producing your own silence. Basically the only way that can happen is if you are dumb enough to actually admit that you copied Cage's silence.