To hear Dalby’s voice on that winter’s London afternoon, to be lured into his tale, raised the hairs on the back of my neck, setting off a shiver that has only just subsided nine months later, sending me on a trail to discover more about Krakatoa, to understand the eruption not from today’s remote vantage but through a lens fashioned nearer his own time, hence the props: this lamp to light the books that piled the desk in the garden shed, the tight blue jacket with its missing button and rough material that rubbed a rash into my neck, the coils of rope on which I rested my feet, the tin of coal tar creosote I would open to suffuse the shed with scent, the music hall songs and shanties I played at first, later substituted by a sound effects score I composed to honour the sonority of Dalby’s memories, to honour the “weird groans and whistles …the loud rumblings [that] got louder, they seemed all round us, the gusts increased to such a hurricane as no man aboard had ever experienced … the winds seemed a solid mass, pushing everything before it and roaring like a huge steam engine, shrieking through the rigging like demons in torment.”

The sounds that comprise Marshland (Helicotrema Mix) were all recorded on the Dengie Peninsula, an area of tidal mud-flats and salt marshes that lies between the estuaries of the rivers Blackwater and Crouch. Microphones were submerged beneath the rising tide, held above retreating waves, wedged into a decaying wooden watch-tower buffeted by strong winds and lowered through the gun slits of a pill-box, where nesting swifts called to fledglings and flew in and out the Second World War concrete structure’s openings. Though left raw and unprocessed, the sounds have been layered in a series of movements between interiors and exteriors, between what passes over and what happens underneath. This Essex coast once formed part of what archaeologists have named ‘Doggerland,’ a mesolithic land bridge which joined Britain to continental Europe, and the recordings were made during fieldwork for a film project with Chiara Caterina in the weeks before the UK population voted on the referendum to leave the European Union.