Whosefault?

  
An old lady had finally had enough, and called police. "Officer," she said when they arrived, "Please talk to the people next door. Every night they have been pounding on my wall and yelling at me until four o'clock in the morning."

"I guess you can't get a wink of sleep," said the officer.

"Oh, it isn't that." The woman explained. "It's that I can't enjoy my piano playing."