If anyone is curious about Beethoven's life, I can recommend and excellent and relatively recently published biography: 'Beethoven: Anguish and Triumph', by Jan Swafford.

We see figures like Beethoven and Goethe as geniuses themselves, but the 18th century conception of 'genius' was not of a person, but of a sort of holy spirit that blessed an individual with great abilities, while remaining separate from that person.

So prior to Romantics of the 19th century taking hold of the concept of genius and re-purposing it into the one we're familiar with today, one would not speak of someone being a genius, but being graced with genius. Genius was not who they were, but something external to them that they possessed.

It's a subtle but interesting difference.

This was arguably the golden age of German culture. Even if Kant just passed away, you had philosophers such as Hegel in Berlin, Fichte, Schelling living at the same time and the younger Schopenhauer actually meeting with Goethe, although that did not turn out well. At that time, Romanticism was taking off in Germany, after the Weimarer Klassik around Goethe, Schiller and people such as Herder and Wieland was coming to an end. Goethe had a reputation of protecting his status and suppressing other talented artists. It should also be said that Beethoven's ninth uses text from the Ode to Joy, from Schiller, who was a friend of Goethe and one of the few he might have seen as equals. Overall, a giant, intricate network of historical figures.

"No doubt Beethoven chided Goethe along these lines, and the most revered writer in the land would not have taken kindly to any sort of dressing down, friendly or otherwise."

No doubt? I'd say no evidence.

The population then was about 1 billion.

With 7.6 billion people, greater access to education, and more travel, how many meetings of comparable people happen today?

I love the description Goethe provides of Beethoven's personality. We've all met that guy, extremely talented, contempt for the world which you kind of admire but seriously dude could you give it a rest? I'm trying to enjoy myself...people are always the same. only the technology changes

   Beethoven would be making techno

Why? Given that making techno, or modern pop music in general, is basically trivial. Just spin up Ableton, press a few buttons ... boom, 10 minutes later you've got a competitive techno-track that doesn't sound all that different (apart from mastering maybe) from what's being played in the clubs. There is no art left in pop-music -- trivial and generic.

A genius would be horrified by the trivial repitition of the same that is modern pop-music.