Classical Music Review: Casken premiere; Philharmonia / Slatkin Royal F estival Hall, London

The enchantment of a piece by John Casken begins with its name. Stellar constellations, legends and creatures of myth have all stood guard over his title pages, and in his latest work, premiered on Tuesday by the Philharmonia Orchestra at the Royal Festival Hall, the choice fell on Sortilege, the French word for sorcery, magic and spells. Even so, the enchantment's more than skin deep. Charms mean games, a sense of which is important to all his music. Games are a balancing act between freedom and restraint; artistic games, no less than acts of gambling, are points of contact with the mysterious power of raw destiny.

Not that Sortilege itself was anything less than meticulously argued and presented. As in his previous orchestral pieces, Orion over Farne and the recent Violin Concerto, the command of instrumental forces, including prominent tuned percussion and those rare concert-hall visitors, the flugelhorn and bass oboe, was ingenious. The mystery lay wrapped in the programme, a tale of corruption at the court of King Arthur, as told in Tennyson's poem Merlin and Vivien. The treachery of the latter against the former involved more voluptuous charms than those involved at the court of Birtwistle's Gawain. Yet in another sense, and without irony (a commodity rare in Casken's oeuvre), the more compelling magic was a question of how this Pre-Raphaelite text acted on what we actually heard.

Music tells tales through its power of impressions and onomatopoeia, and through games of arrival and departure that the story suggests through signposts of its own making. Strong on atmosphere, Sortilege followed its own path with regard to narrative, not to its own disadvantage, but through a firm sense of a purely musical direction. A hypnotic first canto, full of woodwind tracery and riven with impulsive outbursts, was followed by a longer movement that led, via some of Casken's most delicate imaginings to date, to a racy conclusion of violent energy released and expressed. Unequal yet indivisible, both parts turned apparent innocence into menace and deceit, just like the wiles of Vivien. As in other Casken scores, knowing the programme was an essential part of grasping the musical mood. But just how the poem paced the notes from bar to bar was a gameplan the composer kept quietly to himself.

Despite their cosmic reference, the titles in Holst's Planets Suite are vague enough for listeners to impress their own feelings within this set of extended genre pieces. Heard live, as distinct from their usual setting of ambient muzak, they impressed not only for their sheer brilliance, but for the enigma of their composer, reserved and ascetic, yet rising for once to a pitch of orgasmic fury - and all without a whiff of folk- song. Leonard Slatkin, leading American conductor of English music, directed a terrifying "Mars", and a no less disturbing "Saturn", bringer of old age - and, with the Philharmonia strings in The Lark Ascending, offered violinist Christopher Warren-Green a hushed background of utter pastoral serenity.