Birmingham Opera Company’s production of Mittwoch aus Licht, Karlheinz Stockhausen’s six-hour sonic exploration of light, love, and the boundlessness of the human imagination, was a triumph from start to finish, and an unforgettable experience. Graham Vick’s spectacular production fostered a sense of child-like wonder that continued unabated throughout the night.

The work, written between 1995 and 1997, is one of seven operas by Stockhausen in the cycle entitled “Light: The Seven Days of the Week”. Mittwoch aus Licht was the sixth of this cycle, and consists of six sections – a Wednesday greeting, four scenes, and a farewell, all of which were staged in the two enormous halls of the disused factory. The “narrative”, if there is one, is an abstract homily to light, depicting the reconciliation of Eve, Lucifer and St Michael on an intergalactic scale. The setting fitted the spatial requirements of the piece so well it could have been specially built for the event, and Birmingham Opera Company’s production marks the world première of the piece in its entirety.

At 4pm the audience – a capacity crowd of 500 – took up their positions on little stools in the middle of the entrance hall. We were plunged into darkness, and the excitement was palpable as we were transported to Stockhausen’s electronic soundscape via speakers stationed on four corners of the room. Beams of light sporadically illuminated startlingly vivid and other-worldly images that were staged in the space around the audience: a young man running along with a red and yellow kite flying behind him; hundreds of heavily pregnant women walking slowly towards stationary men looking towards the sky, and young men clambering up the walls. The strangeness of this sonic and scenic world was completely immersive and disorientating – time seemed to stand still – but after 45 minutes or so, a door in the back corner of the hall was opened to radiate yellow light, and the audience was led by its glow into the next chamber for the first scene, World Parliament.

The scope of the staging was mind-boggling: the audience, sat, or reclining on grey foam mats, were encircled by hundreds of large yellow “thrones” on 10-foot-high stepladders. These were then filled by suited delegates from each country, their faces painted with the designs of different national flags. The wonderfully resonant choir, Ex Cathedra, and non-singing delegates discussed love in “unknown” and known languages, gesturing to each other in constantly evolving phases of body language, ranging from bureaucratic indignation to sensual release and welcoming affection. However, despite the beauty of the vocal music, the evening also had moments of levity: when a man in a security vest interrupted the singing to announce that a car had been illegally parked outside the venue, I believed for a moment that this was a genuine complaint. However, as soon as the number plate was revealed to begin with “‘M’ for Mittwoch”, it was clear that this was a Stockhausen device that ensured that the audience never felt they were part of an ordinary performance event: although it is described as an “opera”, Mittwoch never feels remotely like a recognisable artistic experience.

Following the interval, it was time for orchestral musicians to exhibit their abilities as extraordinary individuals, capable of participating in Stockhausen’s electronic soundscape. The next section, entitled The Orchestral Finalists, was viewed from a lying position, looking up at the ceiling, where several captivating virtuosi were suspended from the ceiling. The ground was populated by actors who were thrillingly committed to evoking the varying landscapes – from the sea to the jungle – of their solos in turn. The Helicopter String Quartet, which followed, was wonderful on both a musical and a human level: the musicians executed their demanding parts with panache, while the Q&A session after they had landed revealed fascinating insights into their experiences.

The penultimate section of the night consisted of The Michaelon: an awe-inspiring masterpiece of stagecraft and musical skill featuring hundreds of singers (the superb London Voices) and actors who basked in the glow of a blinding “sun”. Here the promised camel made its appearance, and it did not disappoint: it danced and sang, and defecated seven coloured orbs of light (representing a different planet for every day of the week) in a memorable ceremony that was both hilarious and miraculous. Whilst it could be argued that the obscurity of Mittwoch’s content is alienating, the connection the work made with its audience is a credit to the power of Graham Vick’s production, and, indeed, emblematic of his work with Birmingham Opera Company as a whole.

Every so often there is a theatrical event so spectacular and rare that you feel, in the words of Stockhausen, “changed forever”. This was one of those events. At the curtain call after the Wednesday Farewell, pride beamed from the faces of the hundreds involved, recalling the Olympic opening ceremony: this was a fitting addition to the wonderful London 2012 Festival, and an achievement on a truly Olympian scale. It was a privilege to have been there. Congratulations, Birmingham Opera!