Edison Records
Thomas A. Edison invented the phonograph, the first device for recording and playing back sound, in 1877. After patenting the invention and benefiting from the publicity and acclaim it received, Edison and his laboratory turned their attention to the commercial development of electric lighting, playing no further role in the development of the phonograph for nearly a decade. Edison's original phonograph recorded on sheets of tinfoil and was little more than a crude curiosity, although one that fascinated much of the public. These earliest phonographs were sold mainly to entrepreneurs who made a living out of traveling around the country giving "educational" lectures in hired halls or otherwise demonstrating the device to audiences for a fee. The tinfoil phonograph was not fit for any real practical use and public interest soon waned.
Arthur C. Keller
Keller's invention of a "moving-coil" playback stylus made possible the first hi-fi records. In 1931-32 Keller made the first known stereophonic and high-fidelity recordings of orchestral music. On April 19, 1938 Keller was issued US patent number 2,114,471 for his idea of recording the two channels of a stereo recording in one record groove each at 45 degrees from vertical.