In live performance Sam Smith sometimes seems to forget about the audience. Eyes half-closed, hands hugging elbows or buried in pockets, his attention is so tuned to his otherworldly voice that everything in this world disappears. It makes for riveting listening although the same can’t always be said for the viewing. Sometimes it feels like all the emotions escaped through his mouth before they could reach his face. But who cares if he’s not outwardly expressive? Such natural gifts and impeccable technique have charms of their own.