MacMillan's new work develops his `dialogue of extremes' - between dissonance and harmony, innovation and tradition. Robert Cowan applauds his skill

There was a definite thematic continuity about Thursday's LSO Concert at the Barbican where, between the grainy narrative of Sibelius's En Saga and the dancing triplets of Beethoven's Seventh Symphony, Sir Colin Davis conducted the world premiere of a work that brought us both narrative and dance. James MacMillan's Cello Concerto is a big piece (40 minutes, arranged 15-10-15), bigger than The World's Reasoning - the first phase in a planned triptych reflecting the passage of Holy Week - though presumably not as expansive as a "large symphonic score" that's in the pipeline for next autumn. The programming context was identical to that which, a few weeks earlier, had brought us Colin Matthews' Cello Concerto, though here it seemed especially appropriate.

MacMillan's Concerto extends the "dialogue of extremes" that has proved a pivotal aspect of his earlier work. It opens with a bang, and keeps the soloist busily employed virtually for the duration. It is, in a word, a "real" Cello Concerto - lyrical, combative, rich in dialogue and scored with a skill that suggests innovative imagination and a marked respect for tradition. Mstislav Rostropovich was both its prompting agent (together with the LSO, that is) and its first interpreter, and if his highly demonstrative stage manner was anything to go by - nodding approvingly at key tutti and quivering passionately at every solo entry - he believes in its many positive virtues.

The first movement, "The Mockery", cues yapping muted brass, a "stately" waltz, proud plainchant-style chorales and a closing cadenza that fades - very gradually - from heartfelt protest to an almost imperceptible whisper. In a pre-concert talk, MacMillan explained how Rostropovich had sent him home at the last minute to revise the cadenza - a wise move, given the music's effectiveness. The finale fades in similar fashion, rising in pitch this time and punctuated by the fierce, percussive hammering that has been a significant "leitmotif" throughout the work.

The second movement ushers in bright, celestial chiming and filigree woodwinds, although when the finale breaks through with images of rain, wind and thunder (MacMillan's use of percussion is second-to-none among his peers) the drama greatly intensifies. The Cello Concerto's design rests heavily on an imaginative juxtaposition of dissonance and harmony, grotesque dance tunes and the ritual blare of tonally bolstered plainchant. "Scottish Schnittke" murmured a colleague, though I'd prefer to think in terms of a shared Northern candour. The Concerto's closing moments recall the stark, echoing retreat of Stravinsky's Les Noces.

MacMillan's Cello Concerto played to an appreciative full house. The performance seemed first-rate; there were hugs all round and Sir Colin Davis returned for a big-boned account of Beethoven's Seventh Symphony. He'd already treated us to a generously dramatic En Saga, and that generosity extended to the symphony where, in addition to taking his time and bending the musical line, Davis gave us the first-movement and scherzo repeats - though not the finale's. He was truly in his element shovelling vigorously at the staccato crotchets that lead into the first repeat, signalling heavy vibrato with his left hand, bouncing, swaying and generally having a whale of a time. It was as if he had finished his day's work and was finally being let out to play.