It didn’t always go well between Haydn and Beethoven, but musicologists have blown it up somewhat. These days we think in camps, but it wasn’t that bad, otherwise Beethoven wouldn’t have dedicated his first three piano sonatas to Haydn.
Opus 2 nr. 3 is romantic, innovative, orchestrally inclined and technically so demanding that it is unplayable for most amateurs. Beethoven was present at the birth of a new string quartet by Haydn, op. 74 nr. 3, ‘Reiter’, intended for his second concert tour in London. He probably played the viola part during the play through, and he certainly must have revelled in the wonderful slow movement. This deeply intense music was fertile ground for him in his later works, and also works very well in a lucrative arrangement for fortepiano.