Eighty-five years ago this month, the December 1940 issue of Radio Craft showed the newest idea to come to its attention, namely, this shoeshine boy who installed a radio inside his shoe-blacking case.  He could thus entertain both himself and his customer with some radio entertainment.

No technical details are given, although they should be pretty self-explanatory.  Just about any circuit powered by batteries and with a loudspeaker would be suitable