Placido Domingo, 74, who recently had a surgery in New York and therefore cancelled several performances of the Metropolitan Opera production with Puccini’s Tosca, has made a surprising comeback at the Met’s Golden Horseshoe dinner, held to thank donors who support the organisation. At the end of the dinner, the tenor walked in and sung Nemico della Patria from the opera Andrea Chenier. He is expected to return to the Tosca production on 6 November.