Conductors rarely address audiences mid-concert, but with a relatively unfamiliar work on her programme by one of her own teachers, Leonard Bernstein, Marin Alsop spent a few minutes introducing it to the audience. Bernstein's Serenade, written in 1954, takes as its subject Plato's Symposium. Each of Plato's protagonists and their views on love are represented over its five movements, which together form a substantial work for solo violin accompanied by strings and percussion.

Alsop's illustrated lecture was witty and concise; the great communicator Bernstein would certainly have approved. But his piece, despite its attractive scoring, disappoints with its slender thematic material and garrulousness. The smoky-jazz-club references in the party finale are desperate in their desire to please, and fall far short of the genuinely punchy numbers Bernstein wrote for his Broadway shows. Soloist James Ehnes responded with a direct, sweet tone to the work's lyrical possibilities, but his delicate advocacy wasn't enough to sell it to us, any more than Alsop's more upfront sales pitch.

The Serenade's impact wasn't helped by being sandwiched between two masterpieces, Brahms's Tragic Overture and Tchaikovsky's Sixth Symphony. Though there was the odd careless moment in both, the majestic fatalism of the Brahms was amply conveyed by the London Symphony Orchestra under Alsop, who gave the emotional second subject the strength and surge it needed.

The Pathétique went equally well, with a real sense of desperation to the first movement's climaxes and a graceful lilt to the strange five-in-a-bar waltz of the second. Alsop's decision to pull back the tempo for the last and biggest statement of the manic march undermined its momentum, but carrying on straight into the despair of the finale amplified the devastating power of the cruellest of Tchaikovsky's ironic masterstrokes.