On the hottest and longest day of the year, Franziska Lantz comes to set up for her performance. The day before, I’ve prevailed upon my gym trainer and my boyfriend to shift all the furniture from one side of the room to the other, leaving a big open space at the large south-facing windows and under her suspended sculptures for Franziska to perform. We expect a full audience and are bracing ourselves for hot, thirsty guests, rushing out at the last minute to secure extra bags of ice and cold drinks. The sun is strong, and will stay with us until around 10 pm tonight.

Franziska is slender and sinewy, nimble, and quick with a smile and a laugh. She has explained to me in the past that in order for her to get into the dark spirit of her music, she finds it helpful to disguise herself in headgear, masks or makeup. A while ago, she preferred not to show her face at all. And I can see how, with a face as open, friendly, and eager as hers, she would feel the need to gear up for the raw, aggressive sounds that she produces for a live audience. For now, though, she has set out her instruments, a synthesiser keyboard, Chinese flute, pair of oil drums, on a square blanket like she’s prepared for a picnic. I leave her alone with her friend Howard, who has performed with her before. It seems like he’s there as a muse, to ensure she can access the darkness required on this brilliantly sunny day.

The room begins to fill, and spills out onto the terrace, everyone commenting on the heat, the sweatiness, the need for something cool to drink. Mingling, chatting, glowing with perspiration, some having rushed from work on crowded tubes on this sweltering London day, everyone is in a great mood despite it all. At some point shortly before 8 pm Franziska disappears, and the next moment I spot her, she is at the large windows, disguised with black streaks of war paint and wearing a dress of camouflage fabric, with drumsticks in hand, and starting to beat slowly and insistently on the two oil drums. We all gather around her, as though we’re being called to a ritual, the beat getting louder and louder as we settle ourselves around the room to view her best. Some of us are sitting on the long sofas, some propped against walls and armchairs, others view from the terrace and sit along the threshold. The cross breeze from the open windows and terrace doors feels good, and the absence of conversation and any other noise, save the drum beats focuses me on being present in the room.

After the introductory drumming, she shifts down to the floor where she can operate the synthesiser and sing into the microphone. Ghostly sounds waft over and through a techno beat that starts to sound hypnotic. The Chinese flute adds a ritualistic element, and as I look up at the hanging stones, bones, and rusted hooks, elements of the suspended sculptures she dredged from the River Thames, it’s like she’s summoning some primal spirit that connects these remnants from the past to the present. There are frightening sounds, like the quick insistent beat of helicopter wings, her own throaty moans, sound effects that portend horror and violence. The rawness of the aggressive, tuneless, synthesised percussion makes me uncomfortable, and I’m mindful that it’s hard to reconcile this anti-melodic, antisocial sound with the domestic, hospitable surroundings of my living room. But there is still something seductive and otherworldly about this, and I notice that people seem lulled by the noise, and the energy in the room has shifted from resistance to resignation and acceptance. In fact, most people are stilled by it, almost like they are in thrall to it, or transported somewhere else. It’s the first time I’ve ever thought that there is something attractive and cathartic about surrendering to the irrational.

Franziska ends her performance, and a brief pause between the last beat and the applause is enough to bring me back to the room, the people, the cool breeze, and Franziska’s brilliant smile through her war paint and camouflage. We have crossed the arid zone, and are back home.