Alexander Lazarev is guiding the Philharmonia through the second half of Mikhail Pletnev's Rachmaninov cycle, and, framed by Glinka's Life for the Tsar Overture and Rimsky-Korsakov's Scheherazade, he took on the biggest challenge of all. If the Third is the most searching, most musically complex of Rachmaninov's four piano concertos, then the Fourth is the one that leaves most questions of musical validity unanswered. It requires the most careful attention from soloist and conductor if it is not to seem episodic, inconsequential and sometimes plain misjudged, even in the revised version that the composer produced at the end of his life.

Pletnev's pedigree and Lazarev's experience could not get rid of every trace of miscalculation in the Fourth. The concerto's strange opening, where the soloist pounds away at a chordal theme buried in orchestral textures that seem to be intent on sucking every trace of resonance from the solo instrument, sounded no more convincing than usual. The strange eruption at the centre of the slow movement defeated the attempts of Pletnev and Lazarev at integration just as comprehensively as it defeats just about everyone else.

The rest, though, was a sheer delight. For all interpreters, the benchmark for this concerto is still Arturo Benedetti Michelangeli's 1957 recording, in which the supreme keyboard technician gave the work an impalpable sheen. While Pletnev probed deeper than that, he has the technical capability to provide a similar indefinable sparkle. The piano solo that opens the finale was a wonder in its own right, a bundle of dancing, musical lines, each with its own character and direction; and Pletnev conjured up something special with his every entry. He remains the most compelling of pianists, and one of the very finest of our time.