In the unsung roof space above the Royal Festival Hall, art-noise collective The Neutrinos are putting on an exhilarating and disconcerting show, where music, light, architecture and theatre converge into a bizarre but brilliant immersive experience.

Arriving at the Royal Festival Hall box office, you might be a little disenchanted by the surroundings, which spoke of the hangover of a university graduation ceremony. Stalls selling leavers’ hoodies and careers desks filled part of the reception area. Such a welcome did little to prepare the audience for what was to come as the Klanghaus-goers gathered apprehensively, not knowing what to expect.

But this feeling was instantly transformed when the show began. A guide, who collects bags and provides earplugs, led the audience up the stairs from the carpeted reception space to an echoing stairway. We are greeted by a solitary man, who sits on the stone steps and sings in eerie falsetto: ‘there are unknown unknowns’, generating a sense of foreboding before he leads us through a door to the confined roof space.

Jon Baker greets the audience in Klanghaus (Credit: Helen Maybanks / Southbank Centre)

We begin to move stealthily through a labyrinthine set of poorly lit passageways, ducking through doorways and over benches. The space has an industrial feel with exposed overhead piping exposed and bare walls scribbled with sharpie graffiti. The steady beat of a drum recalls a heartbeat as the building comes to life like a heaving, breathing body.

As the promenade continues, our senses are bombarded with a series of contrasting sensations. The dark interior is momentarily blasted with artificial light from an overhead projector before being plunged once again into an abyss of darkness. With each new location comes a new song: one minute an aggressive howl fills the confined space, then an aching lament and finally an ethereal chant of ‘we are all on air’.

Jeron Gunderson, drummer for Klanghaus (Credit: Helen Maybanks / Southbank Centre)

Finally our troop emerges into the cool twilight as we clamber onto the open roof of the Southbank Centre. Leaving the intensity of the interior, we are confronted with the wide expanse of evening sky and the ring of glittering lights from the London Eye. The vertiginous platform exacerbates the feeling of mystification, every audience member wondering what they have experienced.

Loud music, low lighting and a striking setting make Klanghaus an exhilarating and perplexing experience this July.