Task: Question Understanding
Input (English): Context : Natasha, Pierre & The Great Comet of 1812 is a musical adaptation of Leo Tolstoy's War and Peace, described as an electropop opera, with music and libretto by Dave Malloy and directed by Rachel Chavkin. 
Question : Which is the basis of Natasha, Pierre & The Great Comet of 1812?
Output (English): based on