Composers of the Classical music period started writing cello parts which had an identity of their own. Joseph Haydn (1732-1809) wrote many string quartets, making it a very popular form. His quartets from op.33 were, he said, “written in a new and special way”. All four parts were very clear and individual. There were always four movements: a fast movement, a slow one, a Minuet and Trio and a fast Finale. Haydn often played in a quartet with Wolfgang Amadeus Mozart (1756-1791) and two other players. Mozart also wrote many string quartets and dedicated some of them to Haydn. Three of Mozart’s later ones were written for the King of Prussia who played the cello well, so Mozart gave the cello lots of difficult music to play.