To which Object Hamlet compares himself in Act III?


In Act III, Hamlet compares himself to which object? Why?


He makes his comparison to a pipe or organ. The purpose of doing this is because he believes Guildenstern is playing tricks with him and using him like a pipe or puppet. However, he reassures himself that no one can play him like an instrument or pipe, or play him out from high to low notes easily, it is not that simple rather much more complicated instrument.