why did my record player slow down, speed up, then go back to normal?


why did my record player slow down, speed up, then go back to normal? it all happened within maybe 12 seconds. it slowed down, then sped up immensely, then went back to normal speed. why?
leemurray2007
Lee, has this only happened once or does it do this intermittently? If it happens occasionally I second the speed pot degradation theory. Good starting point to check at least 
Depending on time of day and prevailing weather conditions driving load against the power grid, it might have been a fluctuation in available current in the power grid feeding electric service to your home. It happens on a weekly basis for our power grid. The various fans that help our ancient HVAC system move air in our home will slow then speed up at various times through the day, much too subtle to cause the lights to dim. Once the load stabilizes after 10pm or so all things plugged in are much happier. 
hey guys. thanks for all the responses! it is a belt drive, and i was about 25 minutes into one side of a record (CSNY's 4 way street, side 3, southern man, in case anyone wants to know). It was kind of a humid day. This has only happened once.

thanks again everyone. any input helps.