The purpose of this article is to examine the requirement for “sounds which are just sounds” (Cage 1957: 10: 11), described as realized in ‘Experimental Music’ advocated by John Cage after 1950s. And by doing that, we aim to limit the field of ‘Experimental Music,’ which may provide the illusion as if it has the boundless freedom according only to John Cage’s words.

‘Just sounds’ have appeared after 1950s. They are never “vehicle for man-made theories or expressions of human sentiments” (Cage 1957: 10) and they never carry the human spirit on any level. On the contrary, they are understood as a kind of autonomous beings which develop its own self-formation by itself and represented as one independent constituent element in this world which is equal to the human beings.

In this article, we aim to think about ‘just sounds,’ represented as though they embody and attain the truth of the sound. In order to do that, we examine the requirement for ‘just sounds.’ We will discuss not if ‘just sounds’ without any human sentiments really exist or not, but how sounds can be represented as ‘just sounds.’ That’s why we aim to examine the requirement for Cage’s indeterminate musical works, for it is the prerequisite for the representation of ‘just sounds.’