Look. I don't mind being wrong, but I just don't think you're understanding what I'm saying.
Beethoven started out as a keyboardist, sure. His father made him practice like crazy. At first he was a great performer of other people's works, not a composer. He received some acclaim as a performer and went to Vienna. At Vienna he was supposed to develop his composition skills. Hayden took him under his wing, and let's just say things didn't work out. Ignoring all his other great works (if such a thing is possible!) and concentrating on his symphonies, you can see where he started in the classical form and eventually blew the doors off of it, substituting motif development for the typical lyrical development of the time. His use of rhythm and instrumentation (including a chorus in the ninth) was completely unheard of. Music critics attending his symphonies for the first time were outraged. He was taking a field and innovating. The place he took the symphony, for instance, was somewhere the day-to-day practitioners of the time would never have went.
Glad to continue the historical bantering if you find it productive.
You ask for me to explain redefining writing? Sure as heck it's an ambiguous statement. That's the whole point! We can't see where the field can go because we're not practitioners at the top of our game. That's the purpose of pushing forward. It's not a question that has an answer that I can provide.
Interesting that you would choose Shakespeare as writing schlock. In fact, he did write a lot of stuff that was considered pulp at the time, but not only was his works popular with the masses and sometimes low-brow, he was also cutting-edge. His use of language and meter was, once again, unheard of. I could start listing all the new phrases he came up with that are common today, like "into thin air." Geesh! He coined over 2000 new words! He started a completely new way of constructing sentences in English. Shakespeare was probably more radical than any writer since him, yet he also appealed to the masses. You don't have to choose between popular and innovative. Sorry if I represented it as such.
Of course, Beethoven could have stayed with Hayden and wrote Baroque material his entire life. Shakespeare could have used the common vernacular and still been a very successful writer. There's nothing wrong with just wanting to do one thing the best you can. But doing "the best you can" to me means trying to change the world, not just plodding along in it.