Placido Domingo’s “age-defying stamina fuels not only his performing, but his conducting, the mentoring of young artists and very personal efforts on behalf of humanitarian causes from medical research to disaster relief (he once dug in rubble with rescuers following a Mexican earthquake that took the lives of four relatives). He’s also general director of both the National Opera in Washington, D.C., and the Los Angeles Opera. At times, he seems a man driven, diving with superhuman energy into this next act of his life.”