Why can random notes and a structured Serialist composition sound the same? This Reddit comment cites Ligeti:
The irony, noted Ligeti, was that the kind of music pioneered by Boulez and Stockhausen was actually extremely structured -- but it was so structured that the resulting music came across as random to the listener because the structure was so dense that it was hard to grasp:
"Ligeti expressed that division with forensic detail in 1958, in an analysis of Boulez's infamous piece Structures Ia, one of the icons of the short-lived experiment of "total serialism", in which every aspect of music - not just pitch, but volume and rhythm as well - are subjected to systematic organisation. He revealed the limitations and contradictions of the technique, and the paradox that the results of total determinacy actually sound random, chaotic, and indeterminate.
"Boulez was incredibly angry after he read the article," Ligeti remembers. "He had been very nice with me when we had met before, but suddenly he did not speak to me any more. For 10 years, he was a complete enemy. [...]"
It [a Pierre Boulez's serialist piano composition] sounds even more chaotic. I had a college professor in music who loved to demonstrate a kind of competition: He recorded a performer just improvising notes and rhythms at random. Then he would play the random sample and the Boulez piece back-to-back to a room of students. To the students, both examples sounded the same.
So we have here an example of a composition which is completely structured - all its music determined by a discreet series of numbers, and another piece of music that is virtually unstructured entirely, yet to the listener, they sound the same.
09:02 Of course we can also take things
09:04 too far the other way. Around the same
09:06 time as those total serial pieces John
09:08 Cage was writing his music of changes. I
09:11 say writing, but he was actually using
09:12 chants based on the Chinese I Ching to
09:15 dictate the score. So you could say this
09:17 is the total removal of pattern. Now what
09:20 has struck many people is how similar
09:21 these two apparently polar opposite
09:23 approaches end up sounding. This is
09:25 Stockhausen's Klavierstück III,
09:27 the completely patterned
09:30; and this is Cage's Music of Changes, the
9:33 completely patternless.