There was a time when describing the operation of a record player would have been unnecessary ... couple the platter directly to the shaft of a motor. The belt-drive mechanism in close-up.
This working cardboard record player is one example ... It also takes care of spinning the record itself with a small stepper motor. There are a few other details on this build that tie it ...
No, this is the record player stripped down to its most basic form, and that's no bad thing. Its mains-fed motor runs at a constant speed, for example, so if you want to change from 33 to 45rpm ...