Conversation so far:
What kind of music did Pierre Boulez perform?
He was one of the dominant figures of the post-war classical music world.
How did the examiner's report describe Pierre Boulez?
He was described in the examiner's report as the most gifted—a composer.
What other kinds of music did Pierre Boulez learn about in Paris?
He attended a private performance of Schoenberg's Wind Quintet, conducted by René Leibowitz. Its twelve-tone technique was a revelation to him.Here he also discovered the music of Webern.

Question: Where was Boulez about to go before the war broke out?
Self-contained rewrite: Where was Pierre Boulez about to go before the War broke out?