John Cage was an American composer, writer, artist, and music theorist. Cage was a leader of the post-war avant-garde and one of the first to explore aleatoric music, non-standard use of musical instruments, and electroacoustic music. Aleatoric music is music in which some element of the composition is left to chance, or some primary elements of the work is left to be determined by the performers. He created many of these pieces so that others could perform them and interpret his instructions. I admire these works because they are instructional yet leave open to interpretation of the performer. This allows for a level of randomness that varies from performance to performance, making a body of work that can never really be replicated in the same way.
Here is a link to a video of some students performing his “Imaginary Landscape No.4” (https://www.youtube.com/watch?v=A0BNsBlzQII )