September 4, 2020, by Chris Gell

Oxjam becomes Voxjam!

Oxjam banner

COVID-19 has profoundly disrupted the creative industries. The cancellation of in-person events, performances and exhibitions has seen a surge in the introduction of digital technology to allow people to still enjoy live events.

By Paul Tennent and Steve Benford

Oxjam is a national music event that raises money for Oxfam. Now in its 10th year, Beeston usually hosts the event that has grown to be hugely popular and has raised £150,000 to date. The University of Nottingham’s Mixed Reality Lab has always been a keen supporter of the event with academics, staff and students regularly showcasing their own musical skills. This year, with the need to consider how such a festival could run online, the Oxjam team, with the help of the Mixed Reality Lab piloted “Voxjam” – A virtual music festival, featuring 10 hours of live and pre-recorded music streamed to ticket holders via a community ‘watch party’. Some of this content was also delivered in immersive 360 video format via virtual reality, for those ticket holders wishing to take advantage of an offer of an offer of Cardboard VR headsets supplied by colleagues in Digital Research.

“The arts industry has been hit really hard by Coronavirus restrictions and we were keen to ensure Oxjam still went ahead as it’s a hugely popular community-led event. As we find ways to operate under a new normality technology has never been more important and we hope the work we’ve done for Oxjam could be the blueprint for something larger – possibly nationally – in the Autumn and beyond. We’re working closely with Oxfam, but also looking to connect to local cultural organisations that might feed into a future Nottingham festival next year that utilises this technology.” – Professor Steve Benford

Improving the experience

As well as exploring the practicalities and technical opportunities of delivering a festival online that delivers some of the ‘together’ feel of an in-person festival the Mixed Reality Lab has been exploring how to make pre-recorded videos feel more live. One area of performance that has been hit hard by COVID restrictions has been singing together in choirs. While careful social distancing allows small bands to come together to record, most choirs are still unable to do so. As part of Voxjam, we have been looking at how to let choirs sing together again. While of course it’s not possible to really do it in person, a combination of video multitracking and green-screening has allowed us to create a set of videos where you the viewer feel like you’re in the same place as a singing choir. This video of Beeston’s own Unreliable Voices, wrangled by Choir Leader Steve Barton shows the system in action.

Democratising the technology

In creating these videos, we were keen to find ways to democratise the technology, hoping to make a quite complicated process something that could reasonably be done by any performer with a computer and some basic video editing skills, and without the need for very expensive software. While many performers, including some choirs have produced multi-tracked videos which typically present as a grid of people singing from their own living rooms, our aim has been to make the process of creating multitracked performances that have the look and feel of a live performance easier to produce. To do this, we have developed a new piece of software called Video Magic – which, while still under development, allows musicians to record, synchronise and mix 360 videos with automatic chroma-keying to remove backgrounds and critically including real time rendering – something made possible by the fact that Video Magic uses game-engine technology rather than a traditional video editing suite to render out its “performances”. A side benefit of this work is that it also enables multi instrumentalists to quickly produce video multitracked 360 performances as in this performance by Derby-based folk collective, and MRL collaborators Threaded.

Performances that feel more live

Video multi-tracking is an interesting performance medium, because it shares a lot of characteristics with live performance. A performer has to get each track correct in a single take – as one cannot easily edit in quick fixes, but like a studio performance, there is then the opportunity to clean up or add effects to individual tracks after the recording and even add in background noise – something we would normally be looking to avoid in a recording. The result is performances which feel more live, despite possibly having multiple instances of the same performer appearing.
As part of the Voxjam festival we produced a ‘making of’ video, to give a look behind the curtain at how we made the multi-tracked videos, to give a bit of information about the underlying techniques and technologies employed.

Not too late to enjoy

Despite being a pilot, Voxjam raised over £2000 for Oxfam’s Coronavirus relief fund. It is still possible to buy tickets and watch the whole show on catchup. Simply go to to sign up and enjoy some great music.

Dr Paul Tennent and Prof Steve Benford  are both in the School of Computer Science, in the Faculty of Science, at the University of Nottingham.


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