Glasgow-based artist Luke Fowler brings his unusual one-off musical performance My Gourd Instruments to the Hamilton Mausoleum as part of this year’s Sonica festival. Known to produce one of the world’s longest echoes, the venue proves an apt stage for Fowler’s deep listening production featuring 8 differently sized gourds he brought over from the US – but instead of using them as quaint autumnal decoration à la Marks & Spencer, he takes inspiration from African musical traditions and turns them into instruments.

For 2 performances on a glum November afternoon, Sonica takes a small group of audience members to the mausoleum, which is a 30-40 min car ride from Glasgow centre. Upon arrival, the group gathers in a circle around Fowler and fellow musicians Richard Youngs and Stevie Jones, who in turn sit around a series of gourds equipped with recycled strings from a sitar, a cello – or tomato slicers.

The performance itself, organised around a black-and-white marble sun on the floor, has a subtle, ritualistic feel to it: As Youngs and Jones extracted subdued, eerie sounds from their instruments using bows or metal plates, Fowler placed EBows and varying miniature glass bottles on his gourds to manipulate the vibration ever so slightly. At times, he would get up and carry a quietly buzzing gourd across the small round room as if circulating an offering to bring the thin, vaguely tinnitus-like sound closer to everybody’s ear. All three musicians tend to their separate but interconnected tasks with the sensitive focus of Buddhist monks laying out a sand mandala. The spider web-thin sounds lace into each other slowly without ever reaching a crescendo but rather suggest a continuous sonic ether – spotless, permanent, eerie. At times you think you hear a dog whistle, then it reminds of a heater’s buzz echoing gently in the mausoleum.

The overall effect carefully pulled you into a grey zone between haunting deep listening trance and science experiment – not quite pleasant but completely transfixing. It made the hair roots on my scalp tickle and changed my breathing after a couple of minutes. The clearly audible effect of the different materials on each other, together with the slowness of the performance, also produced a welcome synesthetic experience: you think you can ‘hear’ the careful interaction between dried gourd, glass, metal, wood, fabric. After that show, the moody drizzle on the concrete outside the mausoleum feels amplified by a couple of decibels.