On Nov. 11 each year the British Commonwealth observes two minutes’ silence to remember the fallen in World War I. Of the first observance, in 1919, the Daily Express wrote, “There is nothing under heaven so full of awe as the complete silence of a mighty crowd.”

In 2001, artist Jonty Semper released Kenotaphion, a two-CD collection of these silences drawn from 70 years of BBC, British Movietone, and Reuters broadcasts — he had spent four years assembling every surviving recording. “I really don’t think people will find it boring,” he told the Guardian. “This is raw history.”

Is this a contradiction, an audio recording of an absence of sound? “Unlike the Cenotaph at Whitehall, these recordings are far from empty, with Big Ben drowning out the coughs and uncomprehending children of the reverent, amid atmospheric weather effects, broadcast static, startled birds, and rifle reports,” notes Craig Dworkin in No Medium (2013). “The only truly silent Armistice minutes occurred during the Second World War, from 1941 to 1944, when the ceremony was suspended. Absent from Semper’s discs, those years speak the loudest and are by far the most moving.”