We know François-Xavier Roth’s winning way with this repertoire from his recordings accompanied by his own period ensemble, Les Siècles. Here, with London’s most French-sounding orchestra, he gives some equally beautiful performances. The “Prélude à l’après-midi d’un faune” is ravishing and exquisitely graded, while La mer has muscle and fiber. In Roth’s hands, it is Debussy’s great symphony in all but name: powerful, far-reaching, and cogently argued. Its canvas is laid out superbly by these terrific players, who respond to their Principal Guest Conductor wholeheartedly. Ravel’s Rapsodie espagnole, painted in very different colors, is equally striking, a glorious explosion of sound.