A programme of French music under the baton of the LPO’s talented young principal guest conductor Yannick Nézet-Séguin should be a treat. Nézet-Séguin’s affinity for French textures and gestures has already been amply proved, as has the orchestra’s own aptitude for them, yet whatever was happening to the Fauré Requiem last night at the Royal Festival Hall was neither polished nor delightful. To attribute it simply to a bad day might be the kindest thing, but when you take into account the sold-out hall, the Saturday-night profile of the concert and all the people who had come to London’s major classical venue expecting a quality performance of core repertoire, such lazy musicianship deserves neither kindness nor the applause the audience gave so generously.