 Boulez's First Piano Sonata, completed in 1946, has two movements.It was his first twelve-tone serial work (together with his Sonatine for flute and piano), and he originally intended to dedicate it to René Leibowitz, but their friendship ended when Leibowitz tried to make "corrections" to the score (, quoted without a page reference in ).The Second Piano Sonata of 1947–48 is an original work which gained Boulez an international reputation.