I could have worded that better: to make its point about sounds and, if you please, music, it depends on nonmusical cultural expectations that surround musical performance. Its adherence to the outward trappings of musical performance in the 20th century prompt the audience to perceive what occurs during it as part of a "performance". Apart from that, there's nothing more musical about it than sitting alone in a meadow — which I think was essentially Cage's point.

That I find myself using the word "point" so often here emphasizes, to me, that Cage was engaging in philosophy rather than musical composition.