If you’re interested in checking this out, a really good place to start with aleatoric music is Charles Ives’ “The Unanswered Question”[1]. If you listen to th

If you’re interested in checking this out, a really good place to start with aleatoric music is Charles Ives’ “The Unanswered Question”[1]. If you listen to this you can get the gist of the idea very quickly: The composer writes the trumpet call exactly but the relationship between the trumpet and the strings (representing the “wisdom of the sages” if my memory serves correctly) is somewhat random. Although every performance of the piece has broadly the same effect they are not exactly similar. There were two main thrusts of aleatoric music - American and European, with the European school having big compositional elements that were pretty much fixed and the random elements being ordering etc (main example, Stockhausen’s late Klavierstuken) and the American school where there was a much more radical aesthetic and more randomness overall (Cage being the principal exponent) both in composition and performance. So Cage embraced randomness in composition using first Tarot and coin flips and later I-Ching divinations to decide almost every element of compositions and then also gave the performer liberty to make various decisions as well.[2] Like lots of things in music, the classical tradition was not first to aleatoricism, with Jazz and various folk forms of music having elements of this long before straight music. [1] https://youtu.be/vXD4tIp59L0 https://youtu.be/vXD4tIp59L0 [2] The ultimate/most notorious expression of this is of course 4’33”, where the audience and performer jointly experience whatever random sounds occur during a specific period of time but don’t actively do anything at all. Perhaps a more approachable intro to John Cage would be his music for prepared piano, which shows him on the path to giving up more control of the music, because the nature of prepared piano is such that the sounds are going to be very variable from performance to performance but within broad guidelines.