During this final period, he composed several notable works, including the difficult Violin Concerto, Op. 36 (1934/36), the Kol Nidre, Op. 39, for chorus and orchestra (1938), the Ode to Napoleon Buonaparte, Op. 41 (1942), the haunting Piano Concerto, Op. 42 (1942), and his memorial to the victims of the Holocaust, A Survivor from Warsaw, Op. 46 (1947). He was unable to complete his opera Moses und Aron (1932/33), which was one of the first works of its genre written completely using dodecaphonic composition. Along with twelve-tone music, Schoenberg also returned to tonality with works during his last period, like the Suite for Strings in G major (1935), the Chamber Symphony No. 2 in E♭ minor, Op. 38 (begun in 1906, completed in 1939), the Variations on a Recitative in D minor, Op. 40 (1941). During this period his notable students included John Cage and Lou Harrison.