Researchers at California's Berkeley Lab have digitally restored a Thomas Edison phonograph tinfoil recording from 1878. Experts say it's the oldest playable recording of an American voice and the first-ever capturing of a musical performance. (Life's Little Mysteries has called the latter claim into question.) The project is a collaboration between Lawrence Berkeley National Laboratory and the Library of Congress. Researchers used optical scanning technology to replicate the action of the phonograph's stylus, reading the grooves in the foil and creating a 3D image. That image was then analyzed with a computer program that digitally recovered the original recorded sound.