John Cage wrote the piece, 4'33" , in 1952, which consisted entirely of rests. The performers were expected to follow along the time signature diligently and turn the notation pages at the appropriate times yet not play a single note, the point of the piece was to showcase the ambient sound of the audience as music in and of itself.
Here is John Cage talking about the piece in an interview in 1982.
Apparently, the Beatles were very influenced by the book by John Cage titled Silence, published in 1961. His experimental ideas on the blurring of the distinctions between sound and music were to have a big impact on the Beatles' later work. This piece, Two Minutes Silence is an obvious nod to John Cage's 4'33".
Ironically, Soundgarden included a song called One Minute of Silence on their album, Ultramega OK and credited John Lennon for "writing" it. The fact that John Cage is not credited , yet John Lennon could actually be credited for "writing" the piece speaks volumes for the broken copyright system we currently find ourselves in.
And now it seems that the Hitler meme even has something to say about John Cage.
On a final note, did you notice that the elapsed time on each of these videos divided approximately in half as they went from one to the next? Does this say something about our attention span? Probably just coincidence...