Recent mention of the later symphonies of Roy Harris in the thread on "Deservedly Unsung..." led me to start thinking about those composers whose later years were in different ways and for varying reasons blighted or undistinguished.
Composers may retire from teaching or administrative positions but there is no conventional imperative to cease composing. The inspiration or muse which impels a composer often lasts for his lifetime. He goes on composing and many composers not only 'die in harness', so to speak, but produce some of their greatest works towards the end of their lives. Many of the greatest composers fall into this category: Bach, Haydn, Mozart, Beethoven, Schubert, Wagner, Brahms, Dvorak, Tchaikovsky, Bruckner, Mahler etc etc. It is, of course, perfectly true that composers in previous centuries, with some very obvious exceptions, tended to die at a younger age.
There are however others for whom this is not true. In some caes serious ill-health affected their capacity to compose. In others it seems that their inspiration began to wane.
It would be folly to generalise. Each composer's case is different. But we know that Rossini wrote virtually nothing (apart from the Petite Messe Solennelle) for the last twenty years of his life. Sibelius is the obvious example of a 20th century composer whose famous silence for the last quarter of a century of his life and whose destruction of those works he appears to have been working on in the 1930s is equally well-known.
Aaron Copland wrote nothing after the mid 1970s as he succumbed to Alzheimer's Disease. The same sad illness curtailed the compositional career of Sir Lennox Berkeley. No doubt there are other instances.
I reckon however that there are other cases which demonstrate that, for differing reasons, a composer had simply run out of inspiration or creative energy.
Would that be true of Sir Edward Elgar, for example

After the Cello Concerto of 1919 did Elgar produce anything further before his death in 1934 to match the earlier masterpieces
Does the same apply to Sir Arnold Bax after around 1939(the 7th Symphony); Bax died in 1953. Or what about Sir William Walton after he reached the age of 65 in 1967; Walton died in 1983. Are these composers later works not pale shadows of the genius they had demonstrated in youth and middle-age

In mentioning Elgar, Bax and walton I am simply picking three British composers as examples of what I am trying to get at. If one looks to other countries then there are, naturally, other such composers one could discuss-in the USA, Roy Harris and Samuel Barber spring to mind.
To live with and love the music of certain composers is one of the greatest pleasures in life. And to reflect on what they might have done had they lived longer-as with Mozart, or Schubert, or Tchaikovsky, or Mahler-is always interesting as an exercise in total speculative day-dreaming

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But it is also rather sad, sometimes, to think about a composer whose later works evidence an appreciable decline in quality-as has been my recent experience in listening to the later works of Roy Harris. It is so very sad when one is almost forced to think that the composer in question would have been better to have stopped composition altogether.
(I hope this rather stream-of-consciousness, very late-at-night post is not the most dreadful ramble and that someone else at least understands the issue I am trying to identify

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