Joan Peyser wrote a biography of a French composer who was born in what year?
Pierre Boulez Pierre Louis Joseph Boulez CBE (] ; 26 March 1925 – 5 January 2016) was a French composer, conductor, writer and organiser of institutions. He was one of the dominant figures of the post-war classical music world.
Roberto Gerhard Robert Gerhard i Ottenwaelder (] ; 25 September 1896 – 5 January 1970) was a Spanish Catalan composer and musical scholar and writer, generally known outside Catalonia as Roberto Gerhard.