Scholarly discussion of the music of John Cage.

[Dionisis Boukouvalas <>]

Excluding indeterminate works, I always thought that one has to perform Cage's music as accurately as possible.
Nevertheless, there is an example from the marvelous "American masters" documentary where Cage and co are performing "Speech" and where Cage instructs the others to move freely in the space "as people with radios do". I have performed the piece and I recall that the score does not mention something like that. It's really a pity that I didn't know before the performance because I would have loved to do it that way too. So, what it is?
a) Was the idea dropped when the music came to be printed?
b) Are such liberties concerning the space/scene and not the music itself allowed by Cage? But in that case, doesn't the movement in space radically change the music itself?