Like many people of my generation, I suspect, my first exposure to Philip Glass was via his soundtrack to Godfrey Reggio’s 1982 film Koyaanisqatsi. I probably saw this film for the first time sometime in the late 80s at the Duke of York’s in Brighton, where it was a staple of late-night double bills, and it quickly became a firm favourite thanks to Glass’s pulsating score just as much as to Reggio’s mesmerizing visuals. Some years later, I saw the Philip Glass Ensemble perform this piece and Powaqqatsi as live soundtracks at the Barbican, which seems to have been the venue for almost all of my live encounters with Glass. I also saw him present one of his symphonies (no idea which one) at the Barbican sometime in the early 2000s, which was filmed and broadcast live on BBC4, oddly enough; and I even caught up with him in Salisbury City Hall, of all places, at around the same time. In 2007, I travelled to London from Vienna to see Book of Longing, his collaboration with Leonard Cohen, and the epic Music in 12 Parts, my favourite of all his compositions. Now, five years later, I found myself doing the same thing again, this time to see his opera Einstein on the Beach. (Although Glass is a globetrotter, frequently giving performances of his own music, he has never played in Vienna in the six years I’ve been living here.)

Glass is by some distance my favourite composer of classical music, yet I’m well aware that he is regarded with sniffiness by some elements of the classical establishment. The reasons I like him are, I suspect, not entirely dissimilar from the reasons for that sniffiness: his prolific output, his high public profile, what many consider a relative lack of complexity to his work, his readiness to appeal to the heart over the head and his persistent exploitation of a number of specifically limited musical tropes. In short, Glass behaves almost like a rock musician, an attitude that is fine with me.

What I like most about Glass’s music, though, are his glorious, pounding ostinatos and arpeggios, those vast maze-like constructions in sound that seem to go on forever, endlessly multiplying and revivifying themselves. There are few more vital and euphoric sounds in all of contemporary music, to my mind, and they are all over his score for Einstein on the Beach, his groundbreaking opera realized in collaboration with theatre director Robert Wilson. Wilson was known to me – I vividly recall his haunting installation HG, shown at the old Clink Prison in London in 1995 – but this was the first time I had seen one of his theatrical productions. It couldn’t really fail, and it didn’t, instantly becoming one of the most beguiling and memorable live performances I’ve ever witnessed.

In its advance publicity, the Barbican made great play of the fact that audience members were free to come and go as they wished during this five-hour, no-interval performance. In practice, though, very few people left their seats. I certainly didn’t leave mine until the time came to give the cast a hugely deserved standing ovation at the end. Consisting of nine 20-minute scenes and five interludes known as “knee plays”, the opera proceeded with scant attention to plot or narrative but still kept me engrossed from start to finish. There was just so much to marvel at, so much that took the breath away: the dancers with their beautifully choreographed movements, the spaceship scene with its stunning wall of light, Andrew Sterman’s powerful tenor sax solo in the ‘Building’ scene, the virtuoso violin of Antoine Silverman, the miraculous, word-perfect singers, the uncanny calm of the infinitely repeated numbers: in sum, the transcendental interplay between light and darkness, sound and silence, words and music, movement and stillness. Einstein on the Beach is a landmark achievement, nothing less than a reimagining of the limits of theatre in the modern age.