Boulez, Pierre. (1925–2016) & Souzay, Gérard. (1918–2004) "Improvisation I." - Autograph Musical QuotationVery uncommon AMQS from important French composer and conductor, one of the major innovators and forces in 20th century music, who has here neatly penned a short quotation from Improvisation I, part of his longest work, Pli selon pli. Boulez has written out one measure and the title of the movement, "'Le vierge, le vivace et le bel aujourd'hui' (Mallarm)", signed and dated Salzburg, August 20, 1992. On the verso, a further autograph and inscription