Originally Posted by BobbyOne
Dan, It was just reverse: Haydn who wrote only second class symphonies before he learnt Mozart's masterpieces learnt a lot from them. Without Mozart even the latest Haydn oeuvres would have stayed totally dull.
Boy, have you got your history and chronology mixed up.
Haydn started writing his emotional Sturm und Drang
symphonies (nos. 43-48 ) around 1772. Mozart was 16 at the time, and his output had extended to K. 150s and 160s. Mozart's symphonies of this time went up through no. 22, K. 162--years away from and hardly as noteworthy as his much more mature 1786 Prague Symphony no. 38, K. 504.
Haydn's rather advanced Paris Symphonies (nos. 82-87) were written 1786-87, when Mozart was finally reaching musical maturity with Koechel numbers in the late 480s-early 500s.
Mozart very much admired and respected Haydn. Why else would he have dedicated his greatest String Quartets nos 14-19 to the elder master. (They are now universally referred to as Mozart's Haydn Quartets
, from 1782-85.)