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.
Sound film
In 1919, American inventor Lee De Forest was awarded several patents that would lead to the first optical sound-on-film technology with commercial application. In De Forest's system, the sound track was photographically recorded onto the side of the strip of motion picture film to create a composite, or "married", print. If proper synchronization of sound and picture was achieved in recording, it could be absolutely counted on in playback. Over the next four years, he improved his system with the help of equipment and patents licensed from another American inventor in the field, Theodore Case.