“Since there could be no such thing as the absence of sound for a living, breathing human being with a pulse, what then could silence be? It was a matter of intent, Cage decided: The essential meaning of silence is the giving up of intention. Silence is not acoustic. It is a change of mind. … Does listening to random sounds we do not intend to hear – the drone of an airplane engine, a dripping faucet, the roar of a bus pulling away from a stop – constitute the experience of silence? Or does silence end the moment sounds actually impose themselves on our consciousness?”