Though not so little known as all that. In his early 40s, Edward Elgar could take some satisfaction from the success of his choral works around the festival circuit of Birmingham, Leeds and the Three Choirs. But he had yet to achieve a major orchestral break in London. Meanwhile, it irked him that he still had to make up much of his income teaching the violin to young ladies around Malvern - but it was at the end of just such a wearisome day between 20 and 24 October 1898 that deliverance was to come.
Elgar often later recalled how he had arrived home tired and begun doodling abstractedly at the piano, when his wife suddenly asked him to repeat a phrase she found striking, and how, to amuse her, he had then improvised on the phrase to suggest the mannerisms of their various friends. The idea of a kind of musical portrait gallery rapidly took shape, and by the 20 February 1899, Elgar had completed his Variations for Orchestra on an Original Theme (Enigma), Op 36. First performed in London on 19 June 1899 under the great Hans Richter - friend and interpreter of Wagner, Bruckner and Brahms - the work was more or less immediately recognised as a defining masterpiece. Definitive of what? Well, for a start, of a singularly complex musical - and not only musical - personality. What is one to make of a composer behind whose almost every note echoes of other composers are to be detected, yet who never sounds other than himself; whose style, while it is drawn almost entirely from such Continental masters as Schumann, Wagner, Brahms and Dvorak, yet seems so quintessentially English; and whose technical mastery was so deeply dependent on the extra- musical concerns of his daily life?
Given his Schumannesque love of musical puns and cyphers, for instance, it seems possible that what set him off on that fateful October evening was fiddling around with the rhythm of his own name, which fits the first four notes of the original theme - so producing the coded self-reference he duly labelled Enigma. Or was he disconsolately fingering the intervals of the phrase "never, never, never" in Rule Britannia, which has been plausibly suggested as the solution to the claim in Elgar's programme note: "Through and over the whole set, another and larger theme `goes', but is not played" - the work, after all, pictures an emblematic cross- section of British society. Similar musical allusions and extra-musical references are to be found in all the ensuing variations - from the echo of the slow movement of Beethoven's Pathetique Sonata at the beginning of Nimrod to the evocation of the then Hereford organist George Sinclair's bulldog, Dan, tumbling into the River Wye - yet, as the critic of The Athenaeum wrote after the first performance: "As abstract music they fully satisfy."
But what evidently most impressed listeners from the start was not just the "national" scope of Elgar's musical imagery, nor the "European" scope of his style - which, in fact, he shared with Parry and Stanford - or even the professionalism and virtuosity of his orchestral scoring, though this was new in British music, but the complete authority of his utterance. In the upbeat year to a new century, a major master had suddenly declared himself, transforming the possibilities of the tradition from which he had come with a single, talismanic masterpiece. And while subsequent generations of British composers - Vaughan Williams and Holst, Walton and Constant Lambert, Tippett and Britten - were to pursue very different artistic agendas, all sooner or later came to revere the composer of the Enigma Variations as the start of it all. Nor was the work's significance only local. From St Petersburg in 1904, where it delighted Glazunov and Rimsky-Korsakov, to New York in 1910, when it was conducted by Mahler, it served notice on musicians and audiences that British music was once again to be taken seriously, and it has held its place in the international repertoire ever since.
Yet not least of the work's fascinations is its uniqueness in Elgar's output. Before 1899, his efforts had been mainly confined to what the market wanted - lyrical salon pieces and choral cantatas, for which he already showed a characteristic talent. Over the next two decades, by contrast, he was to tackle the forms of oratorio, symphony and concerto on the most elaborate scale, pushing his innovations in structure, harmony and orchestration to far more sophisticated ends than anything in the Variations. Yet it's possible to feel about those later great works a certain strain as Elgar strives to knit the disparate patches of invention that he habitually worked with into seamless continuities - whereas theme and variation form had offered him the possibility of building up a large-scale structure by a balance of contrasts without the need for seamless links. Indeed, with the arguable exception of the grandiose final passage, which Elgar was persuaded to extend after the first performance, one is tempted to hail the Enigma Variations - in its unforced synthesis of public and private manner, of small-scale form and large-scale design, of invention and pacing, colour and expression - as well nigh note-perfect. That the insipiently fevered and fissiparous cultural world of 1899 could throw up a work of such wholeness was already something of a miracle. A century on, anything remotely like it is inconceivable.