It's 17 years since Michael Tilson Thomas stepped down as the London Symphony Orchestra's principal conductor. But he returns regularly, and there is now talk that he might be open to a second stint at the LSO's helm when Valery Gergiev moves on. If the evidence of this concert is anything to go by, it would be a terrific move for the orchestra, who played superbly for him.

The second of Tilson Thomas's current trio of Mahler concerts focused on the ever-astonishing first symphony, one of the most original works in the orchestral repertoire. The American's approach was refreshingly postmodern, avoiding the portentousness that can easily weigh this piece down. Tilson Thomas obtained a tightly structured and unindulgent reading, brisk in tempo, but never at the expense of the work's dramatic array of colour and detail. The strings were as filigree delicate in the spectral opening as they were beefily muscular in the Ländler second movement. The woodwinds deserved medals throughout. The eight horns rose from their seats to play their exuberant final phrases. Best of all were the passages in which Tilson Thomas simply let the orchestra play off the leash, to heady effect and a sure sign of mutual trust.

This concert stood out because of the companion work Tilson Thomas offered before the interval: Berg's Chamber Concerto of 1925, a concert rarity. It is a typically personal and original piece that has neither models nor imitators and, even though the concerto is nearly 90 years old, Tilson Thomas felt the need to preface the performance with some well-chosen illustrations and a talk. Once heard, however, the chamber concerto is never forgotten (a revelatory Pierre Boulez Roundhouse performance nearly 40 years ago still lingers in my mind), and with soloists of such complementary brilliance as the imposing Yefim Bronfman and the poised Gil Shaham to spark off, the LSO winds produced a glitteringly incisive performance.