The London Symphony Orchestra is marking the appointment of its new principal guest conductor with a couple of concerts labelled Daniel Harding: A Portrait. The first offered a curious programme, preceding Mahler's Seventh Symphony with Rameau.

Even the Mahler was a rather daring choice. It is the least popular of the sequence, and not only Mahler's critics but aficionados voice doubts about its overall success. It says a lot for the conviction as well as the accomplishment of Harding's interpretation that he proved the doubters wrong.

It was still a mixed performance. The LSO brass were on world-beating form but the string tone could have done with more depth and sheen. What the reading lacked was a strong sense of character in the presentation of Mahler's highly idiosyncratic thematic material. One of the reasons the Seventh is neglected is that it is hard to work out what this vast but enigmatic work is about. It includes some of the darkest and most ambiguous writing Mahler ever penned, especially in the three central movements with their grotesque scherzo surrounded by a pair of phantasmagoric "nightmusics". By the time the last of these was reached, Harding and the orchestra were up to every teasing hint in the piece; they went on to deliver the finale's vortex of activity with consummate brilliance.

The first half consisted of a suite of instrumental movements from Rameau's opera Hippolyte et Aricie. A slimmed-down ensemble provided an approximation of what a period orchestra might sound like in these delightful pieces, while underlining the fact that this is repertoire in which the LSO can be easily outclassed - which is not the case with Mahler.