Conversation so far:
What kind of music did Boulez perform?
orchestra.
How did the examiner's report describe Boulez?
CANNOTANSWER.
What other kinds of music did Boulez learn about in Paris?
he first heard an orchestra, saw his first operas (Boris Godunov and Die Meistersinger von Nurnberg) and met the well-known soprano Ninon Vallin.

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?