Here is the operative passage from Ross' text:
His lucid approach to classic works of early modernism, particularly the Second Viennese School of Schoenberg, Berg, and Webern, changed how that music is played and heard. Simon Rattle, one of many forward-thinking conductors who received Boulez’s encouragement, described the status quo: “What one heard was only a struggle.” Boulez took away the struggle—the muddiness and the messiness. As if seen through polished glass, the music assumed an unearthly beauty.I am inclined to agree, but I think it is necessary to clarify the nature of the struggle. One element came with Arnold Schoenberg's decision to add Hauptstimme (primary voice) and Nebenstimme (secondary voice) markings to his scores. This seems to have led to a slavish allegiance to Schoenberg's priorities without necessarily grasping the logic behind them. However, the more serious problem came with the move into the use of the twelve-tone row. Amateur mathematicians, such as Milton Babbitt, were quickly drawn to how Schoenberg's technique involved working with a limited number of permutations of the twelve chromatic pitches. This led Babbitt to jump to the conclusion that the foundation for Schoenberg's theory must be the abstract algebraic theory of permutation groups.
It is unclear if Schoenberg knew or cared what Babbitt was trying to do. Fortunately, we do know his famous caustic remark in a letter to René Leibowitz:
I do not compose principles, but music.Unfortunately, by the time I was an undergraduate, music teachers seemed to prefer drinking Babbitt's Kool-Aid to reading Schoenberg's letter.
Perhaps it was because Boulez had his own intense brush with permutations and the "principles" behind them that he came to realize that there was music behind those principles that was "where the action was." Boulez may thus have been the first high-profile conductor of Schoenberg's music after Schoenberg's death to chuck the mathematics and worry instead about where the music was. Boulez turned out to be very good at doing this, perhaps because he was already beginning to grasp where the music was in other composers, such as Olivier Messiaen. Rattle would then emerge as another such conductor, and it now appears that Rattle is willing to credit Boulez for encouraging him into that frame of mind. Meanwhile, Babbitt's work has been pretty much forgotten. As one of my former colleagues put it:
No one is afraid of Uncle Miltie any more.