The piece Arabic Numeral (Any Integer), to H. F., more commonly known as X for Henry Flynt, is one of La Monte Young’s best-known works. It requires the performer to play an unspecified sound, or group of sounds, in a regular one- or two-second pulse for as long as the performer wishes – Young’s own performance consisted of about six hundred beats on a frying pan. This monosonic approach is antithetical to John Cage’s polysonic method, although the results may be similar in the emphasis that they place on processes of listening. As Cage said,
[Young] is able either through the repetition of a single sound or through the continued performance of a single sound for a period like twenty minutes, to bring it about that after, say, five minutes, I discover that what I have all along been thinking was the same thing is not the same thing at all, but full of variety. I find his work remarkable almost in the same sense that the change in experience of seeing is when you look through a microscope. You see that there is something other than what you thought was there. 
Cage had shown in 4’33’’ that silence is in fact constituted by sounds on which there is normally no focus; for his part, Young uncovers the variety that exists a priori in any act of listening, even in the case of the seemingly monotonous. Roland Barthes has written, Hearing is a physiological phenomenon; listening is a psychological act. This leads from the acoustic fact to the subject’s interpretation, from the sound to the audience, and accords with Young’s interest in the audience as a social situation.
 John Cage, cited in Conversing with Cage, compiled by Richard Kostelanetz (London: Omnibus, 1989), 203.
 Roland Barthes, The Responsibility of Forms (Berkeley: University of California Press, 1985), 245.