For a decade or so, Jorja Chalmers has been performing saxophone and keyboards with Bryan Ferry. She’s a dazzling presence on stage, as befits Ferry’s carefully curated and casually sophisticated image, plus her contributions to his concerts can be outsized. During a recent, pre-Covid performance at the Greek Theater in Los Angeles I attended, the backup singers on the iconic song “Avalon” lost their way in the final section. Ferry looked wide-eyed at Chalmers, who swiftly crossed the stage to guide the singers back in sync. Ferry, clearly grateful for Chalmers’s cool, shrugged off the misstep.