John McCabe was born in 1939 in Huyton, Lancashire, of mixed Irish-Scottish, German-Finnish descent, yet his is a decidedly English outlook, down to a passionate devotion to cricket. Until the late 1990s, it was a truism that although one of this country's most distinguished composers he was better known as a pianist of extraordinarily wide repertory and sympathies. His complete recording of the Haydn piano sonatas in the mid-1970s (now available as a set of 12 CDs) was rightly hailed as 'one of the great recorded monuments of the keyboard repertoire'. Subsequent recordings include pieces by composers as diverse as Bax (including the piano original of the First Symphony), Rawsthorne, Satie, Hindemith (Ludus tonalis and the Suite1922) and Herbert Howells. McCabe is an acute commentator on music, and is author of two BBC Music Guides, Bartók Orchestral Music and Haydn Piano Sonatas, plus studies of Rachmaninov (Novello) and the book-length Alan Rawsthorne: Portrait of a Composer (OUP, 1999). In the 1970s and 80s, McCabe also served in a variety of administrative and advisory posts, including the London College of Music (as director, 1983-90), the Association of Professional Composers (as Chairman, 1985-6) and the general council of the Performing Rights Society (1985-8).

Since 1995, however, his public profile has altered, and it is as a composer that he has enjoyed his most far-reaching successes. This has been due partly to the celebrations of his 60th birthday in 1999, with the concomitant release of several recordings of his works (including piano music performed by himself, three of his string quartets, the Fourth Symphony - Of Time and the River - and Flute Concerto), but also to the commercial and critical acclaim afforded to his score to the award-winning ballet Edward II. Originally commissioned by Stuttgart Ballet with choreography by David Bintley and given its premiere by that company in April 1995, Bintley took Edward II with him on his assumption of the post of Artistic Director of Birmingham Royal Ballet later that year. The ballet was given its UK premiere in Birmingham in 1997 and toured Britain. Its London premiere, at Sadler's Wells Theatre, came as part of its 1999 revival and afterwards BRB's orchestra - the Royal Ballet Sinfonia - recorded the score for Hyperion, the two-disc set being released in 2000 to coincide with the Company's performances in Hong Kong.

McCabe's catalogue of compositions is formidably large, embracing almost every form imaginable, from works for his own instrument - notably four concertos, a quintet, a trio and several large-scale solo works, including the Haydn Variations (1983) andTenebrae (1992-3) - to a wide variety of chamber and instrumental music (including five string quartets, a cello sonata and a sinfonia for organ), several highly regarded pieces for winds and brass (including the four-times recorded Cloudcatcher Fells, now a brass band classic) as well as a sizeable body of orchestral works. In this last category feature five symphonies (the most recent largely extended from the score ofEdward II) and two dozen concertos, of which latter form he is the most natural and successful exponent currently writing in Britain. He has produced at least one concertanté work (not always titled concerto, as with Rainforest II for trumpet of 1987, part of a series of ecologically inspired works) for most of the standard orchestral instruments, as well as 'double' concertos for viola and cello (1965) and oboe and clarinet (1988), and the acclaimed Concerto for Orchestra which was given its premiere in 1984 by the late Sir Georg Solti.

Given the drama inherent in the concerto form, with its oppositions of soloist(s) and orchestra, it is no surprise that McCabe has been drawn to overtly theatrical forms, although he has yet to produce a three-act grand opera. His first success in this medium was with the children's opera The Lion, the Witch and the Wardrobe (1968), but it is with dance that he has become associated especially. Several concert works had been adapted into ballets by others - the song-cycle Notturni ed Alba (1970), the Second Symphony (1971; the symphony was itself partly inspired by Peckinpah's film The Wild Bunch) and the suite The Chagall Windows (1974), this last choreographed by Rosemary Helliwell under the title Die Fenster. McCabe's first original ballet score dates from 1973: The Teachings of Don Juan (1973, after Carlos Castaneda's book) for Northern Dance Theatre. Two years later came his first full-evening affair (like Edward II based on a historical figure), Mary, Queen of Scots, written for Scottish Ballet to Noël Goodwin's scenario and given its premiere in Glasgow in March 1976.

McCabe's second collaboration with David Bintley involves not one but two ballets, based on the shadowy figure of King Arthur. Just as Edward II as depicted by Bintley and McCabe was essentially derived from a literary source - Christopher Marlowe's great play (c.1590-2, well known in Germany through Brecht's celebrated reworking of it) - so too is Arthur. However the antecedents of the 'Once and Future King' are far more complex and evolved over a much greater timespan. The legend of the fifth century warlord who led the Romano-British fightback against the invading Anglo-Saxons has been of enduring fascination for writers and audiences across western Europe for over a thousand years. The early references in Dark Age monastic texts (undoubtedly drawing on existing oral traditions) were developed over centuries by many hands, not least in the courtly romances of Chrètien de Troyes. There, as the tales grew in popularity, they expanded into a huge inter-related complex of stories, the 'Matter of Britain', absorbing elements and characters from Late Roman and Dark Age Britain (such as the usurper emperor Magnus Maximus and the seventh-century King Uriens of Rheged), Celtic myth and Christian mysticism. Yet these stories, culminating with the Quest for the Holy Grail, remained fundamentally British, their most elaborate treatment occurring in England in the late 15th century with the publication of Sir Thomas Malory's epic Le Morte d'Arthur. Writers and most recently film-makers have continued to reinterpret the tales into the late 20th century: for example, John Boorman in the visually dazzling Excalibur.

Composers have also been attracted by the legends, their treatments ranging from the songs of the wandering minstrels of medieval Europe to the operas of Wagner and Rutland Boughton. McCabe has steadfastly resisted any influence from these forebears when writing his own music for either of the two parts of the ballet. Indeed, he has confessed that composing the music for Arthur had kept him away from the Ring cycle and particularly Parsifal - with which he had been wanting to re-acquaint himself. 'It is very dangerous when working on a large project like this to listen to another, especially larger, version of what one is trying to do.' The tonal landscape of Edward II was, entirely appositely given its setting, influenced to a significant degree by medieval music (although all but two of the melodies were pure McCabe). In Arthur, he has specifically avoided trying to reproduce a fifth-century soundworld - at best a highly speculative enterprise, given the paucity of material surviving from the time - nor one redolent of the high medieval 'courtly' society where the tales as we know them today achieved their principal shape. There is, however, one brief but significant intrusion from the outside into the music of Part 2 (the score for which is subtitled Le Morte d'Arthur), a brief snatch of melody by William Byrd, from the Kyrie of his three-part Mass. This lies behind much of the musical invention yet only takes concrete shape in the very final scene (as well as in the recent concert work, The Golden Valley, given its premiere in February 2002), where Lancelot, now in Holy Orders, comforts the dying Guinevere.

There are some remarkable set-pieces in the two ballets: for instance (in Part 1, subtitled in the score Arthur Pendragon), the violent seduction of the boy-king by his half-sister Morgan, bent on vengeance, or the nightmare vision of Mordred's birth, grimly parodying that of Arthur's own, conjured by Merlin for Arthur's benefit. Neither ballet's plot, however, affords the kind of opportunity for musical pastiches that were such a vivid part of Edward II - at least none that would work musically and dramatically. 'Most classical ballets have a divertissement somewhere,' McCabe has commented, 'showing off the virtuosity of the company, such as the last act of Raymonda. In Edward, the plot drove the setting to France, necessary for introducing the children - the future King Edward III and Queen Philippa - and putting Mortimer and Isabella on stage alone together. In the first part of Arthur there is no room for a divertissement like that.' Other scenes, such as where Guinevere with her ladies await Lancelot's proxy wooing, or later the assumption of Arthur's nephews into the fellowship of the Round Table, are relatively brief interludes in the action, which would be fatally slowed by the type of formal ensemble scene so relevant in Edward II. The wedding of Arthur and Guinevere in the finale of Part 1 is by contrast too powerful for such treatment. As the composer commented at the time of the premiere, 'you have the wedding … centre stage front, and the terrifying slaughter of children going on behind as Arthur attempts to be rid of his and Morgan's child. It affords the opportunity, without the need for formal wedding music, to tie things up musically with what is required dramatically.' It is also the focal point of the two ballets, Part 2 opening with a reprise as Morgan and Mordred are pursued and escape.

Much of the musical effectiveness of both parts of Arthur lies in a cumulative power, the result of long preparation scene by scene, achieved because of the inherently symphonic nature of McCabe's score - a factor that links it in spirit though not sound to Wagner. As with Mary, Queen of Scots and Edward II, both parts of Arthur are cast in two large acts, each act approximately an hour in length with a degree of internal musical cohesion far greater than normal for a dance piece (except one by McCabe). The cohesion is a natural consequence of this composer's powerfully tonal idiom and the inter-relationship of the various themes developed by wholly musical, organic processes co-existing in symbiosis with the purely balletic demands of the scenario. This is nothing new in McCabe's music; it is audible in those abstract concert works adapted for the stage, as well as others, such as the First Piano Concerto (1966). Edward II compellingly disproved Robert Simpson's famous distinction when discussing Stravinsky - otherwise wholly valid - between the symphonic, with its 'interpenetrative activity of all … constituent elements', and the 'episodic, sectional' balletic. The music of Arthur takes this synthesis of apparent irreconcilables even further than in his previous scores with its motivic integration, striking yet translucent orchestration - nonetheless capable of enormous power - and driving rhythms. A parallel on stage might be the gradual metamorphosis of Merlin, first seen as an old man in a wheelchair, but by the end of Part 1 and in the first act of Part 2 a vigorous, almost timeless figure of awesome power. Most compelling still is the music's longterm design across two evenings, outstripping even Prokofiev's larger ballets, most apposite for the tragedy of Arthur's rise to glory and catastrophic fall.

The scoring of McCabe's highly charged music calls for only a standard sized orchestra, smaller than the large ensemble deployed in Edward II (though that work required a reduced version for use in smaller theatres). Only double woodwind is needed, though with an added alto saxophone often used to represent the avenging Morgan, with a brass complement of four horns (one of which stands for Arthur), two trumpets, three trombones and tuba, plus timpani, percussion, harp, piano (Part 1), celesta (Part 2) and strings. The percussion section, however, although needing only two players, is greatly expanded. Alongside the conventional battery of cymbals, gong, side and bass drums, tambourine, triangle, tubular bells, xylophone and glockenspiel are some more unusual ones for the ballet pit, such as crotales, rototoms and the delicate Agogo bells, used alongside cowbells in the very first scene of Part 1 and again in the first act of Part 2. Part 1 also requires some real exotica, such as flexatone (musical saw), whip, anvil, waterphone ('a kind of metal bowl with protruding metal rods which are played with a cello bow'; constructed specially for the orchestra) and aboriginal rainstick. These extras help to underline the vivid light and shade of Part 1, while in Part 2 their absence - plus that of the piccolo - and the greater roles assigned to the cor anglais and bass clarinet complements the music's generally darker, more tragic atmosphere.

Just as the heart of Edward II lay in its many duos for the principals, so the number three plays a pivotal role in the fabric of Arthur. Three occurs repeatedly in key elements of the music, from a recurring triplet motion to motifs emphasising three notes or constructed from three pitches. On stage, love - or lust - is the primary motivating force with most of the main characters interacting in threes, as in the three love triangles: Uther, Gorlois of Cornwall and Igraine; Arthur, Morgan and Guinevere; and Arthur, Guinevere and Lancelot. The last pair play out their tragic course in Part 2, which also features a triumvirate of knights set on exposing Guinevere's infidelity (Gawain, Agravain and Mordred) and, in the final scenes, a further triangle comprising Mordred, Morgan and Guinevere. Although the action of Part 2 unfolds as one continuous thread, that of Part 1 occurs across three distinct timeframes. The first three scenes of Part 1 Act I deal with Arthur's conception and birth, the three of Act II with the early years of his kingship after the defeat of the Saxons. Part 1 pivots on the drawing of the sword Excalibur from the stone and Arthur's assumption of royal power.

Standing apart, however, are two characters as crucial to the dramatic pacing as is the interval of the third to the music: Merlin and Morgan. Merlin lurks on the sidelines unobtrusively pulling strings except for those occasions when he comes forward and unleashes his power, as for instance when he snatches the baby Arthur and the sword Excalibur from Uther. At the other extreme - the centre - lies Morgan. In many respects she is the central character of both ballets rather than her half-brother, the king around whom the action so often revolves beyond his control. While it is Merlin's machinations that establish Arthur as 'the Once and Future King', it is Morgan's unrelenting determination to avenge her father Gorlois that turns the Matter of Britain into Greek tragedy. A harpy as furious as Medea, Morgan it is whose actions determine the destinies of all. No sacrifice is too great: incest with her brother, the destruction of Merlin, even her own son, created as her ultimate instrument of revenge but whom she kills after he rejects her. At the end, as Morgan abdicates the world to accompany Arthur to Avalon, only the dying Guinevere and Lancelot are left, exhausted, to contemplate the ruin that remains.

GUY RICKARDS