Happy Birthday, br Katy Perry!.br Katheryn Elizabeth Hudson br turns 37 years old today.br Here are five fun facts br about the pop singer.br 1. She began singing br when she was just br 9 years old.br 2. Perry once kept locks of Taylor Swift br and Miley Cyrus’ hair in her purse. .br 3. Her ’Teenage Dream’ album had five No. 1 singles, leading her to tie with Michael Jackson’s record. .br 4. Her hit single, br “I Kissed a Girl,” br was inspired by br Scarlett Johansson. .br 5. Perry’s Super Bowl halftime br performance is the most br watched in history.