The Royal Opera has bitten the bullet so far as Musorgsky’s Boris Godunov goes, and opted to stage the original 1869 version, with no modifications or additions from his revised 1874 edition, which used to be called ‘definitive’ but which seems to be under a cloud nowadays. Rimsky-Korsakov’s version has been pushed right to the back of the doghouse, so that it might soon be revived for its historical interest.