Modern classical music is music written in the 20th century and beyond. Although much of it draws heavily on earlier forms, modern composers also experimented with rejection of long-held ideas; notably, Arnold Schoenberg questioned the traditional notions of harmony with his twelve-tone system[?], and John Cage questioned the very definition of music with his use of chance and found sounds.
... meets Stiva who encourages him in this plan, but, later that evening, Kitty rejects him in the expectation that Vronsky is about to propose to her.
The following morning ...