I'm writing this post with Christian Thielemann’s recording of Parsifalpiping through my headphones. The music is wonderful – sublime, even.

I thought I’d just make sure, because every time I see Parsifal on stage I manage to fall asleep at some point. This time round at Covent Garden was no exception.

Parsifal is designed to be a spiritual experience from which one emerges feeling cleansed and redeemed – and not as a result of a quick nap. As in several of his operas, an outsider intrudes upon a closed community. There’s a unique creation in the form of Kundry, the passive-aggressive female character. Parsifal himself is in a line of Wagnerian archetypes: an innocent fool who is in fact the chosen one.

This is Wagner’s last opera, a culmination of a lifetime of experience and wisdom. Covent Garden’s production does the composer proud at the close of his centenary year, both musically and visually.

Yet, as usual, I zoned out, especially in the monologue sequences. This, I guess, is my problem with Parsifal – a very long work with little plot development. Leitmotifs are pared down to create an austere drama. So we experience Parsifal in slow motion.

Director Stephen Langridge cleverly uses a hide-and-reveal device to show us the back story: Amfortas’s seduction, his downfall and the loss of the holy relic. Klingor’s castration is graphically depicted. A hospital bed dominates the first and last act, a symbol of an organisation (the Knights of the Holy Grail) on its last legs.

Operas often contain incomprehensible plots and it doesn't matter, but in Wagner one can’t separate the music from the text. And his intentions with Parsifal are not clear. Is this a religious opera or an opera about religion? Who is the nameless Redeemer? What is it telling us about sex and faith, or compassion as the key to redemption? Indeed, what is this production at the Royal Opera House trying to say, offering images of the child Christ instead of the Holy Grail? Our esteemed opera critic Rupert Christiansen is similarly baffled.

Personally I think Gerald Finley, who plays Amfortas (quite magnificently), is bang on the money in the trailer, which you can see in full below. He asks what happens to organisations when their leader’s ethics and behaviour are called into question. This is played out in our world daily – think Rob Ford and Toronto, Paul Flowers and Co-op or a certain celebrity chef and her personal brand.

Still, we're talking about four hours of music excluding the intervals. I can sit through Die Meistersinger and come out feeling like I want more. WithParsifal, that's enough. Every time.