Henry Dagg and Evan Parker improvised together for the first time as part of the Free Range series in Canterbury, Kent, on December 2, 2021. For the performance, Evan played soprano saxophone, and Henry developed a new electronic instrument called the Stage Cage, to both process Evan’s live sound as well as generate its own sounds. The Stage Cage includes four valve test-oscillators, a pair of ring modulators, frequency shifter, chromatic zither, and a variable tape delay system (consisting of two quarter-inch tape machines, eight feet apart – the first machine records, and the tape runs past moveable playback heads to the second machine, allowing several replays). Henry's main performance interface is a ‘dynamic router’: a five-key controller, which is the bridge between most of the components of the Stage Cage. 

Towards the end of the performance, the tape machines were stopped, their reels reversed and set to play: the improvisation from then on was overlaid by a reverse reproduction of what Henry and Evan had already been performing, with the reverse recording itself also being subjected to various treatments. The live recording was subsequently developed by Henry for this 56 minute album. Evan notes in the accompanying booklet interview: “I would say it will sound better now, because of the post-production work that Henry’s done, using the live recording as – basically – tracks to be part of a new mix, a new project, which obviously overlaps hugely with what we did in the room, but it should be more detailed and better balanced in certain parts. Some post-production decisions that technology makes possible, where they led to improvements, Henry used those possibilities. It should be better than being at the event …”