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
Happened to me with my older Luxman PD-277.  There are speed control potentiometers for 45 and 33 RPM and they were showing their age.  A little DeOxit cleaned them up.  The wiper contact was a little dirty.
atmosphere is correct. The speed potentiometer might be corroded. This happens a lot on old technics 1200 tt. It's also could be the speed control module. 
If it’s a belt drive, the belt may be stretched or worn. Could be a dirty speed control potentiometer! If it’s direct drive, could be a problem in the servo drive ckt.