This video features the following song:
“Drops of H2O ( The Filtered Water Treatment )” by J.Lang, available under a Creative Commons Attribution license.
Inside whirlpool washer agitators there are agitator-dogs. When the agitator-dogs are bad the top half of the dual action agitator will not turn and your clothes will not get as clean as they should. This video will show how to diagnose and replace these agitator-dogs.
https://www.appliance-repair-it.com/Whirlpool-washer-disassembly.html
https://www.appliance-repair-it.com/washer-agitator-repair.html