Watch on Soap2day. Louis Henderson’s Evidence of Things Unseen But Heard draws a relation between technologies of state surveillance against black communities in Bristol, the rise of sound system culture, and the exceptional character of “Bristol sound”. Shot around the St Pauls neighbourhood, while reflecting on Bristol’s history, which heavily rests on plantation labour and slavery, Henderson stitches a sonic archaeology through archival photographs of the St Pauls carnival and the direct aftermath of the riots of 1980.