Katy Perry- 'Birthday'
By JACKIE WILLIS
It doesn't have to be your birthday to enjoy these celebratory hits. Katy Perry most recently unleashed her slew of alter egos in her new video Birthday, but she's not the first pop star to cash in on growing older.
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Here's our five favorite songs about your b-day, starting with Katy's new hit.
WARNING: Some videos are NSFW.