source <a href=httpscollectionsciencemuseumgrouporgukobjectsco8606388vitaphone disc for sound film sunny 1930 usa vitaphone disc>httpscollectionsciencemuseumgrouporgukobjectsco8606388vitaphone disc for sound film sunny 1930 usa vitaphone disc<a> © The Board of Trustees of the Science Museum London <a href=httpscreativecommonsorglicensesby nc nd40>CC BY NC ND 40<a>