RADIO 'Radioinvito autumn' the nightingale on the microphone; graphics Gian Rossetti. The song of this bird; very dear to the most loyal listeners; it was actually a synchronization signal that preceded the change of origin of transmissions. Advertising postcard for the campaign subscriptions to RAI Italian Radio (Radio Auditions Italian); combined with a contest that is giving away 40 light motorcycles Guzzi. About 1949