Original: Opened in 1860, it became the preeminent music theater of late 19th century Russia, where many of the stage masterpieces of Tchaikovsky, Mussorgsky, and Rimsky-Korsakov received their premieres.
Simplified: It was opened in 1860 and soon became the most important theater for opera and ballet in Russia. Many great operas and ballets of the 19th century were first performed there, including the greatest stage works by Tchaikovsky, Mussorgsky, and Rimsky-Korsakov.