Tchaikovsky’s The Queen of Spades is probably his greatest opera, certainly the one in which his characteristic strengths are on display. Pondering on them inevitably leads one to think about what the operas lack, too, and it turns out be quite a lot. Unlike the finest opera composers, of whom there are regrettably few, he can’t create complete characters: what he is interested in is characteristics, especially — or perhaps only — obsessions, even if the obsession, as with Eugene Onegin, is with not being obsessed with anything, until close to the end.