Most successful child prodigies know that the only thing to do with your parents once you hit 20 is to sue them, not bring them on stage to steal your limelight.

But nobody told the Chinese wonderboy pianist Lang Lang, who, as an encore, got his father to accompany him in a whirlwind solo on the erh-hu - a kind of two-stringed violin, played on the knee - that nearly put the son's dazzling playing in the shade.

Lang Lang had already proved himself in Mendelssohn's First Piano Concerto, written when the composer was only a couple of years older than the pianist. A composer's age is not necessarily a clear indication of the maturity of his or her work (just think of Schubert, who wrote astonishingly truthful scores though he barely reached his thirties), but this carefree concerto is definitely young man's music.

And that is how Lang Lang played it. His opening declamation was quite aggressively crisp, but soon we were reassured that he was capable of tenderness and sincerity too, as he sank beatifically into the key change of the second theme. In the most virtuosic passages of the finale, Lang Lang tended to sacrifice shape in favour of spiky attack and definition, but he was responsive to the orchestra (the London Philharmonic, in fine form), and listening to him revelling in quirky off-beat accents and countermelodies was a pleasure. He is booked to play Tchaikovsky at the first night of this year's Proms: a greater challenge, and an intriguing prospect.

By contrast, lyricism abounded in Rachmaninov's overblown Second Symphony. Otaka encouraged details to come through clearly, creating rasps of musical colour, and the transitions in and out of all that lush expansiveness were effortlessly managed.

But the emotional climax of the concert had already been and gone in a piece only 13 minutes long. Julian Anderson's 1997 score, The Crazed Moon, a tribute to a friend, opened the programme with a profundity nothing else on it could match. A haunting passage for three off-stage trumpets, worrying around the notes that make up the friend's initials, begins and ends the work. After the intensity of the rest of this performance, the reprise brought an extraordinary sense of catharsis.