In the new movie “Katy Perry: Part of Me,” before the pop star appears on screen, we see her young fans. They’re so grateful. In video testimonials that could be straight off YouTube, they stare into the camera and thank Perry — for her inspirational songs, for giving them the courage to be who they truly are.

Lately you can’t escape the rise of the touchy-feely pop star who has clearly taken a particular Beatles song to heart: “All we need is love.”