How did Modest Mussorgsky adapt Pushkin’s Boris Godunov into an opera?

Modest Mussorgsky adapted Aleksandr Pushkin’s historical drama Boris Godunov into an opera by creating his own libretto, which largely utilized Pushkin’s original lines. Mussorgsky’s approach was a literal setting of the play, though he expanded the narrative by adding a Macbeth-inspired hallucination scene for the protagonist.12

The adaptation process involved significant revisions. After his initial 1869 version was rejected by the imperial theatres for lacking a prima donna role, Mussorgsky thoroughly revised the work by 1872, incorporating the new roles of Marina and Rangoni along with several additional episodes.1

Musically, the opera is noted for its dramatic realism, characterized by Mussorgsky’s unorthodox use of tonality and harmony, as well as his method of fusing arioso and recitative. The work effectively balances epic and intimate drama, contrasting the tragedy of the Russian people with the psychological turmoil of Tsar Boris. Following Mussorgsky's death, Nikolay Rimsky-Korsakov prepared an edition that altered some of the original harmonic and instrumental features, though interest in Mussorgsky’s stark, original orchestration was later revived.12