The Classical period saw the emergence of new musical genres like the symphony and string quartet between 1750-1820. Key composers during this period were Haydn, Mozart, and early Beethoven. The Classical style was characterized by clarity, regular phrasing, contrast that became structural or narrative, and motivic rather than melodic material that was "worked out". Examples provided include Haydn's String Quartet No. 3 and Mozart's Symphony No. 40 which demonstrate these Classical features through their use of sonata form, short motivic ideas, and modulation between themes.