Which is more musical, a truck passing by a factory or a truck passing by a music school?
John Cage, "Communication", the third of the Composition as a Process lectures given in Darmstadt in 1958 and published in Silence. Many of Cage's works use sounds traditionally regarded as unmusical (radios not tuned to any particular station, for instance): he really did believe that the sound of a truck and the sounds made in a factory had just as much musical worth as the sounds made in a music school. There is also a suggestion expressed in the quote that in order to determine the artistic worth of something, it is necessary to examine the context in which it exists.