My dear Mikey, if your tenet were true, that there is a limit and we have reached it, then , say, by the time Chaucer penned his Canterbury Tales, making a defining and in his day culminating contribution to language, culture and literary form, would have likewise spelled the end of literature by your terms, viewed in his day at the moment of asking. Evidently it did not, and his literary colleagues and followers did otherwise. :-)
You clearly seem to want another, 'updated' edition of what has already been, this then to be your 'progress':
> A new beethoven? Monteverdi? Debussy? Gluck?
I'm none of those, but my next major work will see the public light sometime in 2014/15 which means that the process of musical art is still ongoing. Becoming a free man as a craftsman makes you part of the Craft, so as long as I keep working, the craft persists. Multiply my efforts by the number of my free colleagues doing the same, worldwide, and you'll soon see there is no 'limit' as you put it.
Our art form & craft is by now so ancient and entrenched it can be a parent to a myriad of talented and skilled children of every hue. Your problem is that you want musical 'designer babies' which, sight unseen, you will know you will like a priori.
Art, I fear, doesn't do (cultural) 'eugenics' to suit you in that regard... :-)
All the very best, warmly, as always,
@ Jefke -- I don't believe the day has yet dawned that I need justify myself to you for breaking preferred silence to post when an alert shows a friend's Q in my mailbox? I've never judged you so why your presumption to judge me? Be still. *N*