Perry is a spark of energy who has found her way in the world.
"Katy Perry: Part of Me" follows the pop star on a one-year concert tour around the world. Cameras catch her in wardrobe fittings, with fans and with family.
Her parents are preachers who've come to accept their daughter is god-loving but on her own path.
The film shows you the work behind the glamour and the help it takes to make all the magic happen. And it takes you inside Perry's mind.
But there is one unhappy ending: The break-up of her marriage to Russell Brand.
He was not included in clips for the film, but the movie does address the sadness, and the old show biz saying, "the show must go on."
You'll see how much Perry loves her fans and how much they mean to her.
"Katy Perry: Part of Me" is full of energy. It's entertaining and it's fun. If you're a Perry encyclopedia, you're not going to learn much, but I think you'll still have fun going behind-the-scenes with your favorite star.
It's a well-produced glimpse of the singer's life -- and I say glimpse because you know there's more to come.
"Katy Perry: Part of Me" is a PG-rated documentary, so it's kid-safe. I'm guessing you'll find your feet moving to the beat.
It goes into theatres in 3D on Thursday.