It isn’t so much that Einstein on the Beach is impossible to summarise, I don’t think, as that it’s just impossible generally. At least, if you were to list this opera’s various constituent elements to somebody, and ask them if it was basically plausible, they would probably say no. Suffice it to say the following: it is four and a half hours long and there is no interval. It has no plot, yet it’s gripping, in a way. The text makes very little sense and relates to both Einstein and the beach only ever tangentially, and most of the time not at all. There is probably more choreography than singing, and none of the opera’s characters (to the extent that there are characters) sing at all. Also, it is one of the later twentieth century’s most ambitious and impressive artistic entities.

It really doesn’t seem likely. But to experience it, you very much have to suspend disbelief anyway. Friday’s first-night performance at the Barbican Theatre was my first exposure to Einstein on the Beach, and it’s not an experience like many others.

At one point, a woman lying on a large bed-like structure recites a short story about a recent visit to a prematurely air-conditioned supermarket, where she noticed some plumed bathing caps which she was not tempted to buy. She repeats this short story many, many times, varying the intonation but never the words, while two prisoners nearby do a strange dance, and a number of people watch who I think are in a court. She gets up from the bed and, standing in front of the prisoners, tries on various items of clothing and flaunts a gun and a lolly, repeating the short story all the while. She leaves. A lawyer then does something similar but this time the text is long and disjointed and about Mr Bojangles.

The body of the opera is made up of a number of scenes which might loosely be described as similar to this. Einstein can sometimes be seen, sitting on a chair at the front of the stage, playing the violin. Between each of the scenes is a ‘Knee play’, made up of entirely abstract connecting material. Two of these are essentially ballet scenes, though somewhat more frantic and confused than any actual ballet, with dancers nipping off stage and back again haphazardly and frequently. Like most elements of the work, these dances betray a structural emphasis on pattern which utterly trumps concerns such as narrative, unity and coherence.

It’s important to remember that Einstein isn’t just a Philip Glass project. It’s actually one of the most brilliantly successful artistic collaborations imaginable. It also makes a mockery of classification, being not so much ‘minimalist’ as ludicrously maximalist. Robert Wilson is the director and designer, and Lucinda Childs is the choreographer – and it was, in fact, the dancing which was most enthralling last night. Childs also wrote bits of the opera’s perplexing, circuitous text, though more of it is by poet Christopher Knowles. The ‘lyrics’ are credited to Glass. These are mainly counting, solfège and nonsense syllables. All aspects of Einstein prioritise pattern and sequence, but absolutely never in a fully logical way. The stylistic mix which emerges is unforgettable.

This particular production – the first since 1992 – is from Pomegranate Arts, and is midway through a tour which has already visited France and Italy. The Philip Glass Ensemble provide the music, under the direction of Michael Riesman, who has apparently led every performance of the piece ever, and unsurprisingly this musical account was immaculate. The performances of the spoken texts were no less immaculate, and the delivery from the principals – Helga Davis, Kate Moran, Charles Williams and the young Jasper Newell – was completely stunning, with a mechanistic, call-centre sort of air.

As for the experience overall, I’m afraid this was let down on Friday night by technical issues. A problem with the flying equipment led to an enforced, unplanned interval after around an hour and a half – and though the subsequent performance was not lacking performatively, after the break the sense of intensity and immersion was somewhat lost, to me at least. The surprising number of cameos from the stage hands elsewhere made it clear that the production had had one run-through too few in this venue. I’d usually consider it poor form to criticise first-night technical issues – but the relentlessness of Einstein is clearly key to its effect, and ruining its flow was a major issue.

That said, assuming these problems are fixed – and I imagine they already are – Einstein on the Beach will doubtless be unmissable, with performances as rare as they are, and with an ensemble and cast as brilliant as this. If you can, go and see it. After all, as the text itself notes, all these are the days, my friends, and these are the days. My friends. It could be those ways.