Stood at the bus stop opposite the Westgate Centre, I spotted the gramophone in the graphic for Oxford in the window opposite. I realised that I have never thought about how a gramophone works. They were wind up and so not electrical. I have taught about record players but their needles oscillated magnets between coils to produce an electrical signal that was then amplified. I have looked up gramophones and I had guessed correctly. The needle is made to oscillate backwards and forwards by the groove on the recording. The oscillating needle is attached to a diaphragm which makes the air oscillate. The horn is designed to make this as loud as possible.
