Aluminum disc

In the field of audio recording, an aluminium disc (or aluminum disk in the USA) is a phonograph (gramophone in the UK) record made of bare aluminium, a medium introduced in the late 1920s for making one-off recordings. Although sometimes used for making amateur studio or home recordings or in coin-operated "record-your-voice" booths at fairs and arcades, during the first half of the 1930s bare aluminium discs were primarily used to record radio broadcasts for the private transcription disc archives of performers or sponsors.