A year before my first Boulez performance, I wrote an essay about what it's like to listen to Boulez in 2009.

...upon repeated hearing, this music does indeed open itself up to the listener. It slowly, reticently yawns forth its secrets to the hearer in unexpected ways. His output is by no means monolithic either, with very thorny yet electric piano sonatas and sometimes breathless long-distance sprints like Sur Incises (cue the linked clip to 4:15 to hear this ‘long-distance sprint’), contrasted by eerily celestial portions of Pli selon Pli and the richly colorful ‘folds’ of the aforementioned Le Marteau.