<Tr> <Td> </Td> <Td> This article's lead section may not adequately summarize key points of its contents . Please consider expanding the lead to provide an accessible overview of all important aspects of the article . Please discuss this issue on the article's talk page . (February 2017) </Td> </Tr> <P> A prepared piano is a piano that has had its sound altered by placing objects (called preparations) on or between the strings . </P> <P> Although theoretically any object could be used to prepare a piano, in practical application preparation objects are usually expected to have certain characteristics: </P> <Ul> <Li> They are applied directly to the piano strings; </Li> <Li> They must fit in the desired location inside the piano; </Li> <Li> They (usually) should not move from their location during playing; </Li> <Li> They must be reversible (that is, when a properly prepared piano has been "unprepared", it should be impossible for anyone to tell that it had ever been prepared; no permanent damage is done to the piano). </Li> </Ul>

Which one of these composers invented the music for the prepared piano