early years "Le matin, Le midi, Le soir" (1761) 1768 longer, rhythmically complex, challenging to play, extremes of dynamics and sforzatos (Sturm und Drang) 1773 more popular styles "Symphony No. 56 in C Major" (1774) 1780's Paris Symphonies composed for public; 1790 twelve London symphonies expanded orchestra, daring harmonic conceptions, thematic inventions