BEHIND-the-scenes documentary that traces her ascent from gospel singer Katy Hudson to the present day with countless awards cluttering up the mantelpiece.

The film captures the impact of divorce on an exhausted Perry as she takes her California Dreams tour around the world, intercut with energetic concert footage recorded at the Staples Center in Los Angeles.

Concert footage showcases her tremendous vocals, as you’d expect, alongside her zany costumes and stage design.

Invariably, it’s the raw footage which makes the biggest impact, and Perry allows the cameras to keep rolling at her low ebb.