It's like the gift of the magi. A woman and a man want to give each other precious gifts at Christmas but they have no money. She has beautiful hair, he has a watch he's very proud of. So individually, they go away and he sells the watch he owns to buy her combs for her hair, and she cuts her hair and sells it to buy him a chain for his watch. That's irony.
Decade music lists? You mean 'nineties', 'eighties', things like that?