Two years on from the disquieting electronic sound collages of her third album, Pastoral, that skewered British nationalism in the wake of the Brexit referendum, Gazelle Twin is back with an audiovisual project for York Mediale.

Absent Sitters is described as a virtual seance in which an online audience will be guided by a performer medium to investigate what is live performance in 2020. Musician, composer and performer Elizabeth Bernholz, AKA Gazelle Twin, developed the work in collaboration with the artist and filmmaker Kit Monkman, and Ben Eyes and Jez Wells at the University Of York Music Department.

"It has kind of transformed over time," Bernholz says of a project that they began developing last October. "The scope for it was quite wide. York Mediale were very kind to commission something that didn't necessarily have a set outcome, so we had a really wide framework to work with, but we knew that it would be centred around performance and to some degree music."

The premise built on Bernholz's holistic approach to music-making. "The way that I create music isn't just to write it and perform it, there's a lot more to it. There's a story behind it, there's usually a persona and a theme. The premise initially was to use that concept and work with these wonderful other artists in creating something that was like a new art form.

"Over time we experimented with all sorts of things. Our early talks were about virtual experiences and using virtual reality tech, which is something that Kit uses in his work sometimes. He works mostly with screen-based visuals, as well as public art experiences using screen-based technology and a lot of musical technology. In my work I use vocal augmentation, or electronic equipment to alter my voice, so we were just messing around with that for a good six months."

By the start of 2020 they had decided to focus on "performance without a performer," developing an idea that Bernholz had done once before based on "a piece of music for performance without me being present performing it, so having other performers but also my voice being present in the music itself.

"This is something that I trialled [with Kingdom Come] a few years ago and it worked really well, so we returned to that but with the idea that there would be a completely absent performer, while the audience would be present. This is an idea we'd had way before the pandemic, so in January when it hit it was quite uncanny because we'd been talking about using an empty theatre based in York with a small, very select audience based on the stage rather than in the auditorium. They'd have this empty space where a performance would happen through various bits of technology, through speakers and radios, so it would be coming in from another place. This idea was born out of the fascination with a seance and collective summoning of something.

"They're very performative things when you look at the structure of them. There's loads of controversy around them as well, mediums as performers and con artists, but there's also this really interesting technological stuff where it plays with the idea of transmitting music and voice through radio and picking up signals."

In the wake of COVID-19 restrictions ruling out all but a small number of socially distanced concerts, the concept became eerily prescient. Bernholz says: "In January we were actually all in the University trying out vocal experiments and on that day the news hit of the pandemic. Actually there was a case picked up in York that day, and it was a really strange, darkening world which didn't really slow down from that point.

"After a bit of a break while we all had to isolate, we realised that this piece was completely related to what had been happening, with musicians having to perform through live streams. It had suddenly become this new - hopefully temporary - version of the industry. So we began to adapt this idea to become a completely online experience but still using all the concepts and the aesthetic and the general idea to create a collective summoning but without being able to have an audience present together in a physical space."

By deconstructing live performance, Absent Sitters seeks to make the audience question what they are witnessing. "I would say the whole thing really is an experiment," Bernholz admits. "We don't know if it will work or not. There's a certain flatness to experiencing something like that online. It's something we're all aware of and what we're trying to do is just see how we can shape the experience to be a little bit more reflective, rather than just plug and play, join this live performance with your headphones on in your dressing gown and then get on with your life having dinner, or something.

"We've tried to make it more of an event and something that people can commit to a little bit more, so there's more that they invest in this experience that is really making their role more essential. Rather than just being an anonymous viewer, they will be part of this, and they will see other people that are taking part whilst they're experiencing it.

"We're trying to experiment with having a sense of a presence; more of a collective presence that you get at a gig or a concert but in this very different, very strange way. It will not be a traditional performance. It will be almost like a sort of ghost of a performance, what we've all been missing since March as performers and as people who like to experience live music.

"There's a lot going on, but we also don't know how it will turn out, which is kind of exciting."

Absent Sitters runs at York Mediale from October 21 to 25, 2020