CLASSICAL MUSIC / Take a hundred players, mix well: Showpieces without a soloist, symphonies in all but name, or a feast of new ideas? Bayan Northcott explores concertos for orchestra

Fifty years ago this month, that great musical Maecenas and director of the Boston Symphony Orchestra, Serge Koussevitzky, unwittingly touched off a tradition. Recently laid low by the death of his first wife, he had begun commissioning pieces in her memory. Already he had advanced a fee for the young Benjamin Britten's projected Peter Grimes. Now he was confidentially advised by the Hungarian violinist Joseph Szigeti and the conductor Fritz Reiner that their eminent compatriot, Bela Bartok, was in difficulties. On 4 May 1943 Koussevitzky signed with typical flamboyance a letter offering the composer dollars 1,000 towards a new work for orchestra.

In fact, Bartok was dying. In the two and a half years since the darkening European situation had forced him at 59 to emigrate to the United States, he had just about supported himself by giving occasional concerts and working on the folk-song collection at Columbia University. But his terrible sadness for his native land had precluded any creative work, and by 1943 he was already suffering from the fevers of undiagnosed leukaemia. Koussevitzky's initial down-payment at least helped towards a summer holiday in upstate New York, where he felt briefly better enough by August to resume composing. He had often worked fast and in this instance may already have found a starting point in sketches for an uncompleted ballet. All the same, his finishing of a five-movement score for full orchestra lasting 40 minutes in just two months suggests the urgency of a composer who knew that his time was short.

A composer also palpably concerned to synthesise on the broadest scale the divergencies of his entire 40-year career. Inimitable frissons of Bartokian night music frame the central slow movement, a blackly jagged elegy of tragic weight. The sonata-form first movement is heralded by a vastly mysterious introduction and throws up brazen flights of neo-Baroque counterpoint. The finale, constructed on an equally capacious plan, encompasses within its headlong sweep of manic folk-fiddling episodes that vary from barnyard humour to aching nostalgia. Why, after a lifetime of suites, rhapsodies and concertos, was Bartok still reluctant to acknowledge the largest concert score of his maturity as a symphony? Maybe he considered the intermezzo-like second and fourth movements lacked symphonic decorum: the one a chain of chattering duets, the other a bucolic plaint interrupted by a savage satire on Shostakovich. Maybe he felt the piece to be too confessional. With his emotional guards down and the sophisticated European audiences who had admired his gritty constructivism between the wars seemingly lost for ever, he certainly found himself writing with a renewed directness. Whatever the reasons - and noting the score's tendency to spotlight varying groups of instruments - he plumped instead for the title Concerto for Orchestra.

He was not the first to use it. That convivial young anti-romantic, Paul Hindemith, had already sought to counter the egomania of the 19th-century solo concerto tradition by modernising the pre-classical concerto grosso, and his brisk 15-minute Concerto for Orchestra of 1925 duly cross-cut chunky tuttis with ornate episodes for concertino groups of soloists - like some augmented latterday Brandenburg Concerto. Too rarely revived, the piece still retains enough vitality and character to make a tonic concert opener, and it inspired imitations in its own time: a somewhat lumpen Concerto for Orchestra (1934) by the Italian Goffredo Petrassi - who was subsequently to add seven more works to the genre - and a vigorous, if predictable, Hungarian-Baroque example (1940) by Bartok's old folkloristic comrade-in-arms, Zoltan Kodaly. Still, the title might have lapsed with the waning of the neo-classical ideal, but for the astounding success of Bartok's own Concerto.

He was just well enough to acknowledge the excited reception of its New York premiere in December 1944 by Koussevitzky and his Boston players, 10 months before his death. Had he hung on a few years longer, he would have seen the work universally accepted as a modern classic, even as a popular repertory piece, and certainly as a creative challenge. Slowly elaborating his own Concerto for Orchestra between 1950 and 1954, Witold Lutoslawski was compelled under the doctrine of Socialist Realism in Stalinist Poland to go back to the kind of raw folk-tunes and traditional schemes that Bartok had long since absorbed and elaborated into his own boldly original technique. Yet the final result still contrived to suggest a step beyond Bartok to the extent that its idiosyncratic overall form seemed to flow the more completely from the contrasts and balances of the orchestral line-up itself.

In the first two movements of the 1963 Concerto for Orchestra he dedicated to Britten, Michael Tippett went further still, more or less abandoning received symphonic procedures. Instead, the orchestra was broken down into small ensembles - nine combinations of wind and percussion in the first movement; three layerings of strings in the second - and the forms simply built up out of their kaleidoscopic shuffling and superimposition (though Tippett rather flunked the possibility of a still more elaborate superimposing of winds, percussion and strings for his finale). Two years later, Roberto Gerhard forsook even Tippett's residually thematic concept in a coruscating Concerto for Orchestra projecting an abstract interplay of mobility and stasis, gesture and texture.

Yet it was left to Elliott Carter in his Concerto for Orchestra of 1969 to exploit the possibility of deriving a total form from a specific arrangement of the players: dividing the orchestra into four 'concertino packs' of mixed instruments and swirling the characteristic colours and configurations of each in and out of focus against the other three in a 20-minute vortex of sound. Meanwhile Thea Musgrave had opened up quite another, quasi-theatrical approach in her 1967 Concerto for Orchestra by instructing certain players to stand up in rebellion against the conductor and pursue their own tempi. Different again was the terse Concerto for Orchestra with which the veteran American, Roger Sessions, crowned his career in 1981, being conceived for the style of a particular orchestra - once more the Boston SO, which the composer had loved for 60 years.

If the notion of the Concerto for Orchestra as it has developed since Bartok were merely a negative one - a catch-all term for a large orchestral showpiece that is neither quite a concerto nor a symphony nor yet a symphonic poem - it would scarcely have generated so outstanding a sequence of works, many of them turning-points in the outputs of their respective composers. A few, perhaps, have fallen short. Richard Rodney Bennett's festive and well-made contribution of 1973 - another Britten tribute - has not stood out in his oeuvre while Oliver Knussen seems to regard his very early example as a youthful indiscretion, though sprightly memories persist from the 1970 premiere of its uproarious Charleston-style finale.

Yet if Bartok's Concerto remains by far the most popular - a standing demonstration against all the shifting fashions over the last 50 years of how to write approachably without sacrificing musical substance - at least one of its younger admirers now seems in the process of creating a whole cycle. Robin Holloway's vast, brash First Concerto for Orchestra (1969) may have been in the nature of a graduation piece, but his Second Concerto (1979) triumphantly revived the Ivesian quotation-collage idea in an infinitely more complex overall form than Ives ever achieved. Now he is at work on a Third Concerto for the LSO, some pages of which are said to total a formidable 80 staves. But then, if one takes all the potential solo and group permutations of the virtuoso modern 100-piece orchestra as a starting-point, the possibilities are presumably endless . . .

The Philharmonia plays Bartok's Concerto for Orchestra, Wednesday 7.30pm, Royal Festival Hall (071-928 8800)