Balance between known and new music

[aukhawk]

But there were LvB's late quartets.  I do, in fact, think that:
1. There is music written which the composer means for us to listen to several times, i.e., music which we are not meant to "comprehend" on one hearing.

Well quartets are written as much for the performers as for the audience, I think.  And they will perform it several times.
Likewise a Chopin salon piece (not that I'm trying to belittle Chopin, not at all, he is a favourite with me) or a Bach French Suite.

But an epic symphony - I enjoy it, but I do struggle to imagine what the motivation is to compose such a thing.  Even though Mahler was a conductor with a fine orchestra at his disposal - essentially it's a self-indulgent thing - like the starving artist who's works only sell long after he's dead - I have more empathy with the likes of Philip Glass who worked as a New York cabbie to make ends meet.  Many of the greatest pieces of music were never heard by their creators at all - why did they do it?  Did they know nothing else?

[Jo498]

Many of the greatest pieces of music were never heard by their creators at all - why did they do it?  Did they know nothing else?

Apart from Beethoven who physically could not hear anymore, but witnessed performances of almost all of his works, it is extremely rare that a great piece of music was never heard by its creator. Schubert is an exception, but really a rare exception among famous composers. He was writing extremely fast and had not yet have a sufficient standing and sponsors to get most of his orchestral music and operas performed. I suppose he lived to hear performances of a lot of his chamber music and lieder. But then he died so quickly after having composed some of his greatest works, he may have missed some.
Other examples, like Mozart's Requiem, Mahler's 9th etc. are just single works, where premature death prevented the author from hearing it performed. Bruckner may be another exception, but I think several of his symphonies were performed in his lifetime. Why do they do it? Because they have to do, I guess.

[Karl Henning]

Apart from Beethoven who physically could not hear anymore, but witnessed performances of almost all of his works, it is extremely rare that a great piece of music was never heard by its creator. Schubert is an exception, but really a rare exception among famous composers.

Incidentally, he doesn't get the press, but Smetana went deaf, too.  Only a small fraction of Ives's music was performed in his lifetime/presence;  a case can be made that some of the music he never heard performed is great.

If our field of enquiry is before the 20^th century, yes, of course, it is going to be the rarity.  But the musical world has changed.  It is no longer reasonable to call it extremely rare.