How startling the reading matter of strangers on the Tube can be. While most commuters content themselves with free papers, self-help books and bibles, you can usually find one buried in something improbable: a Neruda reader; a Mahler score; a Semiotics journal, perhaps.

I have often wanted, but never quite managed, to strike up conversation with someone buried in such an esoteric tome — so I was happy to oblige when a sweet old couple did just that to me and my fiancée as we journeyed home from the Opera House last Tuesday night, both scanning the programme of The Minotaur. Not because we wanted to look smart, I should add, rather because we were trying to fathom the horrors we had just seen.

“Was it any good? My husband and I were thinking of going,” smiled the lady.

I didn’t know quite what to say. Opera is only a recent pleasure of mine, and only because my fiancée sometimes comes by free tickets. Sir Harrison Birtwistle’s take on the minotaur myth is by far the least remitting and most demanding thing I’ve seen at Covent Garden. It’s the operatic equivalent of Joy Division or Scott Walker at their bleakest: all dense rumbling brass and woodwind, hardly any air, still less tunes — and blood. Lots of blood, screeching crows, craws of gore and human tripe.

Its impact is undeniable — the libretto is delicious, John Tomlinson is remarkable, Antonio Pappano’s baton makes sense of the hardest bits, the critics mostly loved it and I have not quite been able to get it out of my head since.

But was it enjoyable? Who, exactly, is this sort of entertainment for? A rich, masochistic, gothic aesthete with a classics degree? There is something perversely amusing that the pinnacle of high art should be quite such torture.

I quite like the thought of some flash banker stumbling into the stalls by mistake. But did I advise a kindly old opera-loving couple to queue up at the box office for cheap returns for it? No. They looked way too nice.

In rep until 3 May (020 7304 4000, www.roh.org.uk)