That's Where the Pee Pans used to come and Play

The story:

Actually, my roommate at the time broke his leg, and had to be placed in a cast that immobilized him up to his hip, and he needed a bedpan to pee in, or what I called a "Pee pan." Then I sang "That's where the pee pans used to come and play, my sister went there on a Saturday." Then he said, "Not POee Pans, Big Bands." "Oh, that makes more sense...." said I.