Work by Stravinsky comp. 1918–20, in memory of Debussy. F.p. London June 1921 (cond, Koussevitzky), Philadelphia 1923 (cond. Stokowski). Pf. vers. of chorale section f.p. Paris January 1921. Rev. 1945–7, with re‐orch. of chorale and considerable changes in orch. of whole work so that 1947 vers. is virtually a different piece.