Katy Perry performed tracks from 'Prism' at her album release event for iHeart Radio in Los Angeles (Oct. 22), looking resplendent in a shimmery, iridescent pink-white dress. She also shared the inner meanings of some of the album's tracks. It was totally Katy's night.

She revealed that 'By the Grace of the God' was written before she let the light in and while it starts out dark, but you can tell she found a way to let the light in as the song progresses.

Regarding 'ROAR,' she said that she wrote the song "to find my own voice," and shared that 'Dark Horse,' featuring Juicy J, was inspired by 'The Craft,' the '90s film about a coven of teen witches who start out having fun before things get out of hand and drift to the dark side of messing with magic arts.

Katy brings the house down.

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She comes to life on stage!

Christopher Polk, Getty Images

What a pretty dress.

Christopher Polk, Getty Images

Watch Katy Perry Perform 'By the Grace of God'

Watch Katy Perry Perform 'This Moment'