Katy Perry: Part Of Me (PG, 97 mins)

Documentary/Musical. Katy Perry, Russell Brand, Lucas Kerr, Shannon Woodward. Directors: Dan Cutforth, Jane Lipsitz.

In less than four years, Californian singer Katy Perry has become one of the biggest selling artists on the planet.

She capitalised on the controversy of debut single I Kissed A Girl with two hugely successful albums, One Of The Boys and Teenage Dreams, and numerous hit singles.

Over the past 12 months, her personal life has been under intense scrutiny as a whirlwind marriage to comedian Russell Brand fell apart.

Katy Perry: Part Of Me is a 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.

"Thank you for believing in my weirdness," she squeals to adoring fans during one candy-coloured musical number.

While her on-stage shenanigans with a dancing cat called Kitty Purry certainly err towards bonkers, Dan Cutforth and Jane Lipsitz's video diary is a conventional fly-on-the-wall portrait in a similar vein to Justin Bieber's Never Say Never.

Thus, we're treated to fans praising Perry as an idol who has given them the strength to embrace their uniqueness in a world of crushing peer pressure.

Concert footage showcases her tremendous vocals, as you'd expect, and her zany costumes and stage design wouldn't look out of place in Willy Wonka's factory.

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

From the moment Brand wanders into shot and Perry swoons, "I think, honestly, I found the love of my life", we're braced for the emotional car crash.

Sure enough, she breaks down before a concert in Sao Paulo, sobbing uncontrollably as the reality of the break-up hits home like a sledgehammer.

By the conclusion, she's able to make jokes at her own expense, wandering around a wedding dress shop with her sister and quipping, "I guess if I see anything I like, I should put it on hold".

Katy Perry: Part Of Me is surprisingly candid, exposing enough fragments of the singer's broken heart to convince us that this isn't just glossy self-promotion.

Energetic performances, including a rousing rendition of Hot N Cold replete with split-second costume changes, are intercut with tributes from celebrity admirers.

"She can write a killer tune," coos Adele, followed by effusive praise from chart rival Rihanna.

To ensure the audience are in fine voice, a restored sing-along version of You're The One That I Want from Grease plays before the main feature including animated lyrics floating in 3D over John Travolta and Olivia Newton John.

:: No swearing :: No sex :: No violence :: Rating: 7/10

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