The silent black and white film displays two women walking along an American street carrying a bulky flip-top phone.
They then attach a wire from the device onto a fire hydrant before erecting an umbrella which has been converted into an aerial.
One of the women then uses the phone to connect to the operator, who plays a gramophone record into a microphone for her enjoyment.
The rare film was recently unearthed in a dusty archive by British Pathé, which is trying to discover more details about the technology involved.
Spokesman Mark Harris said: ”It’s amazing that nearly 90 years ago mobile phone technology and music on the move was not only being thought of but being trialled.