‘Wow!’ said the lady next to me as Mathias Heymann‘s Siegfried soared through the air in his Act III solo, ‘wow!’ too from me, at some of his feats, and ‘wow!’ at the start and end coup de theatre of (spoiler alert?) Odette and Rothbart’s tattered ghosts (?) flying up to oblivion. And yet on leaving the theatre I didn’t feel wowed overall, instead a little underwhelmed. Why?