The 10-second recording of a singer crooning the folk song “Au Clair de la Lune” was discovered earlier this month in an archive in Paris by a group of American audio historians. It was made, the researchers say, on April 9, 1860, on a phonautograph, a machine designed to record sounds visually, not to play them back. But the phonautograph recording, or phonautogram, was made playable — converted from squiggles on paper to sound — by scientists at the Lawrence Berkeley National Laboratory in Berkeley, Calif.”