Debussy writ large

Your task: take eight 'Préludes' and arrange them for orchestra. Simplicity itself? Not if your raw material is piano music by the master of subtlety. Bayan Northcott on the fine art of transcription

Some artists seem to be quite unfairly endowed with creative energy. In addition to writing a vast and varied catalogue of compositions, Dr Colin Matthews has served as amanuensis to Benjamin Britten and Imogen Holst, published many scholarly editions and articles, sat on umpteen foundations and committees for the betterment of his fellow musicians and set up a new music record label for which he works as executive producer. And recently, as a little sideline, he has taken to arranging for symphony orchestra the complete Préludes for piano – all 24 of them – by Claude Debussy.

So far, he has completed eight. And next Sunday evening, in Manchester's Bridgewater Hall, Edward Gardner and the Hallé Orchestra will be giving the first performance of the latest three: an "English" group comprising "Hommage a S Pickwick, Esq", "La danse de Puck" and "Minstrels" (the latter apparently inspired by a group of strolling players Debussy saw while he was staying in Eastbourne). In fact, this entire programme will consist of orchestral transcriptions from piano originals, culminating in Mussorgsky's Pictures at an Exhibition – not in Ravel's ubiquitous version, but a reputedly plainer and certainly much rarer Russian scoring from the Fifties by Sergei Gorchakov.

But then, out of the bald, yet suggestive eccentricity of its piano writing, Mussorgsky's suite has become about the most arranged work in the Western canon, with at least a dozen more or less complete orchestral versions during the last century by musicians ranging from Sir Henry Wood to Vladimir Ashkenazy. Debussy's Préludes, by contrast, must rank among the most intrinsically pianistic pieces ever composed, their musical substance often seeming to arise out of the instrument's very vibrations. Some of them have been orchestrated before: "La fille aux chevaux de lin" quite often, in fact, with its invitation to a solo instrument over purling strings and harp, or "La cathédrale engloutie", scored with numinous elaboration by Stokowski. But what could possibly be the point of arranging most of the rest – apart from the sheer challenge?

There are, after all, notorious disparities between the two mediums. Harp and percussion apart, the orchestra consists entirely of instruments capable of sustaining line and tone. The piano, by contrast, can only create the allusion of a sustained line through techniques of touch and pedalling since, in reality, every note begins to fade the moment it is struck. On the other hand, it is difficult orchestrally to match the percussive clang of a piano chord attacked really loudly, still more to evoke the sonorous power of the modern piano's deep bass register with an orchestral bass comprising such relatively weak or short-breathed instruments as double basses, contrabassoon and bass tuba.

Then there is the complex problem of how to reproduce orchestrally the resonant, blurring effect of the piano's sustaining pedal – only usually to be resolved by the arranger surreptitiously insinuating many additional notes to those indicated in the piano score.

Indeed, Ravel emphatically distinguished between instrumentation, when you find the right combination of instruments for the notes, and orchestration when "you are building an atmosphere of sound around the music, around the written notes". And beyond all this there is an old question of whether it is ever ethical to score up a piece its composer never envisaged for orchestra. Rimsky-Korsakov, a great orchestrator himself, dismissed this as the equivalent of tinting old photographs. Or, if a piano piece is orchestrated, should its arranger ever go stylistically beyond what its composer might have done?

Not that such quibbles would have troubled composers much before the mid-18th century. Up till then, they tended to select instruments emblematically – flutes for pastoral music, trumpets for royalty, and so on – or simply scored for the forces to hand, happily revamping the same music to meet different conditions. What complicated the matter was the gradual evolution of orchestration as an art in its own right – something one can begin to observe, perhaps, in the often piquant and quickly shifting instrumentation of Rameau's later operas – plus the increasing cultural prominence of a single domestic instrument, the piano.

Most 19th-century transcriptions, indeed, were from orchestra to piano, since strumming through piano reductions was how music lovers outside the major cities got to know the orchestral and operatic repertoire before the advent of the gramophone.

Only with the evolution of the piano to its full potential and the expansion of the orchestra to its most vast and various towards the end of the 19th century did the rewards, temptations and questions about the art of orchestral arrangement really emerge. An essentially modern activity, then – or, perhaps, even more essentially post-modern? Over recent decades, when linear notions of cultural history and the autonomy of the individual "work" have increasingly come into question – when it has seemed newly acceptable for an Anthony Payne to compose half of Elgar's Third Symphony or for Colin Matthews himself to spirit up an eighth planet out of Holst's seven – the practices of transcription, arrangement, recomposition and transmutation have become a veritable mania among contemporary composers.

Matthews recalls that even when playing through the Debussy Préludes as a boy, he always felt they were latently orchestral. And, having tested the viability of his project by first tackling the two most extravagantly pianistic of them all – "Ce qu'a vu le vent d'Ouest", and "Feu d'artifice" – for an earlier Hallé concert, he has felt confident to pursue the promptings of his own orchestral ear rather than attempting a self-denying imitation of Debussy's orchestral style. Nor has he scrupled to modify Debussy's substance here and there where he felt the orchestral effect required the space of an extra half bar or so. Indeed, at the end of "La danse de Puck" he has even dared to bring back a harmonic sequence that Debussy's original used only once, because he likes it so much.

Whatever the raised eyebrows at such liberties, Matthews could claim at least a partial justification in the practice of the most consummate arranger of all. Uniquely in the history of transcription to date, Maurice Ravel possessed the imagination and skill to conceive utterly idiomatic piano pieces and then, sometimes years later, to reconceive them so completely in orchestral terms that there is no way in which the unknowing ear could tell which was the original. But the illusion of equivalence in, say, the orchestration of "Alborada del gracioso" from the piano suite Miroirs actually rests on a number of divergences, including the insertion of four extra bars near the end to make a bigger orchestral splash.

One of the recurrent pretexts for making arrangements has been the desire of composers to pay tributes to colleagues or predecessors. Debussy orchestrated two of Satie's Gymnopedies; Ravel orchestrated Debussy's Danse. For obvious reasons, subsequent composers have fought shy of orchestrating Ravel. Percy Grainger's arrangement of "La Vallée des cloches" from Miroirs for tuned percussion is, rather, a transmutation into a gamelan piece.

But recently, that post-modern trailblazer Robin Holloway has scored up Ravel's delectable little piano Menuet "sur le nom d'Haydn" for the Hong Kong Symphony Orchestra at the request of the once so-doctrinaire authenticist Christopher Hogwood. However, in the process, Holloway reveals, he couldn't quite resist extending Ravel's original by the odd 40 bars.

Edward Gardner conducts the Hallé Orchestra in Debussy at the Bridgewater Hall, Manchester (0161 907 9000) on Sunday at 7.30pm