When performers play a musical composition, the noise is there. When they do not, the noise is still there. Noise is everywhere at every time on every channel. The message interferes with the noise not the other way around. When a composer writes a rest he is really allowing the noise to be heard.
Silence is noise.
The application of chance operations to the location and selection of artworks follows the same dictum as that applied to musical composition. Rolywholyover is an isomorphic extension of Cage's metamessages to the medium of the museum. The degree to which these variables are controlled by the score is, to a certain extent, the decision of the composer. Where a conventional composer would try to control most of these variables explicitly Cage gave the responsibility of many of them to the performer. His scores were, in the conventional sense, more like guidelines than decrees.