MUSIC / The view from within: Nicholas Williams on the RPO at the Festival Hall

DIRECTING ensembles and orchestras is at best a half-hearted affair for most composers, but over the last decade Sir Peter Maxwell Davies has become that rare creature - a genuine composer-conductor. The change has come about by his working with the classics he is familiar with as a matter of course, and by conducting the 20th-century repertoire he knows intimately through its direct impact on his own music. Monday's Festival Hall concert with the Royal Philharmonic Orchestra (he is their Associate Conductor / Composer) was the kind of programme where he excels: two major pieces by Sibelius, plus a premiere and a current hit of his own - the concert suite from Act II of his recent ballet Caroline Mathilde, and the rousing An Orkney Wedding, With Sunrise.

Sibelius's influence can be traced in Davies's music as far back as the rugged contours of the 1976 First Symphony, though the model there was Sibelius's Fifth Symphony rather than the late tone poem Tapiola that opened Monday evening. The fascinating aspect of both works by this Finnish master is their absolute command of musical movement, and Davies conducted this strange poem of forest voices, of music stirring itself from fixity to frenzy against a background of rooted tonality, with a composer's insight.

Though all is flux in this shifting, virtually monosomatic score, each stage in the process was defined with clarity and common purpose. There was an unusually prominent French flavour to it; not just in the occasional fragments of Debussian whole-tone scale wafting on the forest breezes, but also in the near quotation from La Mer which whipped up in the storm section.

If all this reflected well on Davies as architect and symphonist, his own Caroline Mathilde - the second suite from the Royal Danish Theatre commission of 1991 - cast light on an early stage of his career. As a Sixties iconoclast, he had employed parody and exaggeration in works like Eight Songs for a Mad King to disrupt conventional responses and open up new modes of feeling.

The ballet, also dwelling on a background of insanity, employs similar techniques to convey the full force of its tragedy. But the techniques have today become almost common practice. True, the concluding alto flute lament, grabbing the audience's affections after textures of sustained violence, was unexpected and heartbreaking even if it represented an expressionist trick at least as old as Berg's Wozzeck. Elsewhere, through much of this seven-movement suite, a parade of distorted courtly dances lurched in and out of focus much as might be expected from a late 20th-century musical setting of an 18th-century costume drama.

A chilling, intense passacaglia offered the most characteristic number, its rhythms barked out by brass and strings. Soprano Nicole Tibbels and mezzo Teresa Shaw sang the wordless chorus during a nightmare scene of hushed suspense. Like Prokofiev, Davies knows how to balance tumultuous action with areas of restraint. It's more than just coincidence that for all their differences of style, Mathilde and An Orkney Wedding share not only a common pattern of distorted-dance sequence, but also the sense of an ending - the rueful lament in one, the bagpiper ex machina in the other - that's essentially theatrical in effect.

Briskly competent in his own works, Davies showed the full measure of his conducting skills as a sensitive accompanist to Tasmin Little's introspective reading of the Sibelius Violin Concert. Horns and woodwind in the slow movement might have argued for a warmer, more romantic approach, but this was essentially a view from within, musicianly, controlled, taking the pyrotechnics for granted.