Topic > ng those years helped shape his musical personality. The first was Messiaen's famous analysis course, the other was René Leibowitz, who introduced him to serial music, where Boulez found "a harmonic and contrapuntal richness and a capacity for development and extension that I have never found anywhere else part". The Structures book was begun in early 1951, while Boulez was completing his orchestral work Polyphonie a, c. , B. The first of the two "chapters" of the second book was composed in 1956, but chapter 2 was not ...