Yet there is plenty of historical evidence for the growing surmise that, given the luck to resist the grosser physical ailments, the constant neuronal renewal of creative activity may actually help to lengthen life. One thinks of Titian wielding his ever bolder brush through his eighties, or of Sophocles in his 90th year confounding allegations of senility by quoting a magnificent speech from his just-completed Oedipus at Colonus. One notes, too, against the medieval and Renaissance backgrounds of plague and strife which must have reduced actuarial expectations to Third World brevity, that composers such as Machaut, Dufay, Josquin, Tallis, Byrd and Monteverdi all succeeded in working on into their seventies; that Schutz composed his own funeral music just before expiring at 87, and that for some 46 years until his death at 86, Telemann supplied Hamburg with annual oratorios in styles up to date enough to survive in the repertoire for years after.
Of course, it could be argued that the longevity of these figures was precisely what gave them the advantage over shorter-lived contemporaries in the artistic survival stakes. Yet most of them had already made a strong showing at the outset of their creative lives, while on the other hand, the early deaths of Purcell, Pergolesi or Mozart hardly inhibited their posthumous fame. To be sure, the notion of youthful doom as part of the very concept of genius took on a new life in the Romantic era of Weber, Schubert, Mendelssohn and Chopin, while even Falstaff, so often cited as the apogee of creative old age, was actually completed before Verdi reached 80. A better example would be Saint-Saens - writing waltzes at three, and still composing with fluency and charm when he died in his 87th year.
But then no century before this can have seen quite so many composers working vitally after the age of 80. Here one thinks at once of the culminating phases of Richard Strauss and Stravinsky; of Messiaen's final feat in completing at 83 his vast orchestral sequence, Eclairs sur l'au-dela - to be heard in its first British broadcast this Friday on Radio 3 - or of Tippett's recently finished orchestral score, The Rose Lake, confidently programmed for his 90th birthday celebrations in a year's time. Alternative cultists might point to Havergal Brian's doubtless unbeatable production of no less than 21 symphonies and oh so much else between ages of 80 and 92, or to the still unexplored perfumed gardens of musical exotica cultivated by the late nonagenarian Kaikhosru Sorabji, some of whose concertos and organ pieces are rumoured to last up to five hours. Meanwhile, among those still writing are Lutoslawski, just turned 80, Berthold Goldschmidt, 90 last winter, the redoubtable Alan Bush at almost 93 - and, not least, Elliott Carter, who is 85 today.
What on earth keeps them all going? After five or six decades of creativity, one would have thought all youthful impulses to lyricism would have long since spent themselves; all determination to surpass rivals, all aspirations to revolutionise taste, to have resolved themselves in the satisfaction of achievement or the cynical indifference of defeat. Is the lure of posthumous fame really enough to account for the continuing urge to produce works in the face of ever- shortening odds against enjoying their acceptance, attending their first performances or even finishing them? Or are we dealing with an exalted order of artistry which has come at last to recognise the truth of Schoenberg's dictum that 'music can say things which can only be expressed in music': that the musical language as it has evolved in the West over the last 1,000 years is capable of conveying, as no other medium, just how the cognitive and affective mind works - and of generating understanding as an end in itself?
Such a notion might make it easier to understand the persistence of a Sorabji or a Bush, despite lasting personal contempt for, or ideological ostracism by, the musical establishment. But what of a Strauss, early celebrated, then long written off; or a Stravinsky, constantly conscious of the historical unrepeatability of a revolutionary masterpiece such as The Rite of Spring written at 30? In both cases, the final works comprise striking, supra-personal attempts to counter the breakdown of Western tradition - those fissile tendencies in 20th-century music which in themselves account for the belated developments of such figures as Tippett, Carter and Lutoslawski - by reaffirming their starting-points all those years before.
So, having lamented the apparently total destruction of Austro-German culture in 1945 in his searing Metamorphosen for strings, the octogenarian Strauss returned to the aesthetic faith of his conservative, horn-playing father; recalling the classical and early Romantic periods respectively in his Oboe Concerto and Four Last Songs with an affectionate nostalgia miraculously purged of all vulgarity. So, despite his continuing efforts to make it serially new, the aged Stravinsky returned to the religious faith of his fathers in the ritual impersonality of his last, penitential masterpieces, Abraham and Isaac and the Requiem Canticles. Besides such definitive achievements, Tippett's attempted third way, as Yeatsian- agnostic trickster-visionary, may have been less perfectly realised in such scores as New Year and Byzantium but is quite as consummatory in intention.
What, by contrast, is so extraordinary about Carter is that the music he has continued to pour forth since his 80th birthday in 1988 shows no signs whatever, either in attitude or in technique, of summing up. Those who have grappled with the labyrinthine masterworks of his middle years - from the craggy First String Quartet of 1951 to the cyclonic Concerto for Orchestra of 1969 - may be pleasantly surprised by the eclectic attractions of the earlier pieces he composed in search of his true self, as spaced through the upcoming Radio 3 Composer of the Week series from next Monday. But it is Carter's evolution since his fifties and sixties, which at the time seemed so culminatory, that is the real wonder: the increasing spontaneity of manner and variety of form by which he has continued to animate his inexhaustible invention.
His short orchestral celebration of 50 years of marriage, Anniversary, which appeared in 1989, for example, proved his subtlest study yet in multiple time-flow - reminding us, incidentally, of the not immaterial fact that the late creativity of Strauss, Stravinsky and Messiaen was also sustained, even driven, by exceptional wives. Meanwhile, the more recent Violin Concerto has displayed a new mastery of the long, self-generating line. And now comes news that a just-completed 15-minute Partita for the Chicago Symphony Orchestra is to be the first stage of a 45-minute trilogy - the BBC Proms getting the second instalment in 1995 - making up the grandest of all Carter's orchestral projects, and planned for completion by the age of 88. After that, a Fifth String Quartet and a commission for the Ensemble InterContemporain are firmly promised. It seems that in five years' time articles like this one will still be asking when Elliott Carter is going to start composing like an old man.
Composer of the Week: Monday-Friday 9.10am Radio 3