Opera in 4 acts, with prol., by Borodin to his own lib. after an outline by Vladimir Stasov. Begun in 1869 and left unfinished in 1887. Completed by Rimsky‐Korsakov and Glazunov; prod. St Petersburg 1890, London 1914, NY 1915. The Russ. musicologist Lamm has shown that Rimsky and Glazunov deleted nearly 1,800 bars of mus., a fifth of the total. An edn. by Levashov, Fortunatov, and Pokrovsky was perf. in Vilnius 1974 and pubd. in Berlin 1978. There are other performing versions.