Rehearsing for a revival brings new discoveries, but the recovery of familiarity comes first. The practical, apparently trivial details that determine much of the emotional contours of a performance - move downstage here, pick up the notebook at the end of suppertime, smoke a Toscana cigar at this point rather than a cigarette - are semi-enshrined in the assistant's score, and often impossible to pick out with any exactitude from the darkly-lit reference video which was often made before the show had reached crystallisation. Yet what I realised, despite my self-caricature as a disembodied type, an intellectual performer, is that after a proper period of rehearsal and immersion in a role which one at the same time invents and discovers, the moves and rhythms of the performance are written in the body as much as the music is programmed into the vocal muscles. The sensations and nuances flood back.

There were changes. In 2007 I grew a Thomas Mann lookalike moustache which my wife and children rather took against. This time, I somewhat ineffectually sprouted a grizzled and greying beard that had even more of the ageing effect the costume designer Chloë Obolensky was aiming for. The impact of actually growing the beard or moustache, rather than wearing a false one, is important in terms of what one thinks acting actually is. For some, to act is a matter of impersonation - Olivier donning a putty nose for Richard III or a pair of false teeth for Shylock, or the increasing tendency in movies (the sort that used to be called biopics) for the actor to become unrecognisable in terms of accent, mannerism, physical build and so on. The transformation can be, is meant to be, astonishing, miraculous.

To make the simple transition from clean-shaven to bearded represents, on the other hand, in its very simplicity and subtle realism, a conception of acting as a matter of rehearsing and performing towards an accommodation between the character as presented in the text and one's own self. As I've already said, you invent and discover. My own experiences, tendencies, habits, moods and memories have to be subsumed into the journey from professional dignity, repression and order to disorder, humiliation and transfiguration which is Aschenbach's in Death in Venice. That's why it is important to me that the novella and opera are not simply about a failing writer who falls inappropriately in love with a teenage boy. The impact of the story and the way it is told is far more universal. It's like Flaubert saying: "I am Madame Bovary." We are all Gustav von Aschenbach.