I was very disappointed by a book that I feel is as inconsequential as the music it represents. Cage has very few ideas, and the ones that he has he drops like a brick on your foot. The fact that we can never experience a 'true silence', as we will hear our nervous system and heart beating, is repeated to death and is quite meaningless. Everyone knows that there are always sounds to be heard, but silence in music means those things producing the music are to make little or no sound.
Most of the rest of the book is some annoying "Zen" babble, with lists of uninspired questions. The only thing I found to be in agreement with Cage about what that he deemed both his writing and his music meaningless, quite true.
I gave this book two stars rather than one because it did show me once and for all that this music is just as pretentious, self-important and unskillful as it sounds, and I no longer have to debate that with myself. Unless I am seriously missing something, or this kind of pointless commentary on pointless music resonates with you, don't waste your money on it.