Creation exists only in the unforeseen made necessary, he once said.
For someone who was nicknamed “Mr. Sang Froid” his contributions to the late 19th-begin 20th century German-Austrian romantic repertoire were remarkable.
From his performances in Bayreuth I have Parsifal (1970), Der Ring des Nibelungen (Cds from 1976 and 1977 and DVDs from 1980) and a performance from Tristan und Isolde from 1969 (recorded in Osaka Japan, this is a Bayreuth on Tour-production). The 1976 Ring is special. It was Boulez' take on the music together with Chéreau's regie that was too much of a breach in the tradition of Wagnerian opera performances than the audience was willing to accept for this centenary Ring. Among booing and other noisemaking, that indicates that a considerable part of the audience is less than amused, there is in Siegfried someone from the anti-Chereau contingent who brings his own whistle. In the saddest tradition of the Jockey Club, a prestigious elite club that terrorized Wagner's Paris premiere of Tannhäuser in 1861, he plays along when Siegfried blows on his own makeshift reed in the second act. There is a frenzy that surrounds these performances and it makes listening to them both exciting and harrowing. A frenzy that I miss, perhaps odd, in the recordings from 1977 (the 1980 performances on DVD were, of course, recorded without audience). With Patrice Chéreau already dead in 2013, both director and conductor of this legendary Ring are no more. It was in vain that Boulez asked Chéreau to look into Parsifal. But Chereau couldn't connect to this opera and declined. Alas.
The last time I saw Boulez was in Amsterdam, the Concertgebouw. It was Januar 2011, now exactly 5 years ago and he conducted Mahler 7 on that occasion. He linked Gustav Mahler to Six Pieces for Orchestra by Anton Webern. By programming it that way, and by his crystal clear reading, he showed us Mahler as a 20th century composer. Away from the 19th century - away from Bruckner and Brahms. He refreshed my view on Mahler like he did with Wagner before.
Boulez was a door to new music. Be it as an interpreter of compositions by Frank Zappa (one way to describe Zappa's efforts in modern composition is "Boulez-lite with a beat", I leave it to the academics to what degree that description is apt) or by his own compositions which I came to know and appreciate pretty late in my music-loving life (with Pli Selon Pli, Le Visage Nuptial, Répons and the hauntingly beautiful Cummings ist Der Dichter as current favorites). Like all great art, Boulez' music is accessible on different levels. You don't have to be a scholar in musical theory in order to appreciate it. Put on a record and just let it happen. It will grow on you (often habituation precedes appreciation). The only thing you need is a body and a pulse (I think Wagner said something like that when he was confronted with concerns about the accessibility of Tristan und Isolde - 4 hours of heavy chromatic music in an opera without any arias). And ears that grew up with movie soundtracks know how to deal with dissonances and enharmonic sounds a lot better than you will, perhaps, give them credit for.
Pierre Boulez had a good taste for polemic but for me he was, first and foremost, a bridge to new worlds of sound. For that I'm grateful.