Don't get mad, get even.

In the case of sweet-as-candy US pop star Katy Perry, the way to deal with failed record deals and failed relationships has been to work, work and work.

The 27-year-old - who has the distinction of being the first female artiste with six number ones from the same album - may look like a Barbie doll, but she isn't just a record label confection.

Before she hit the big time with her songs Ur So Gay and I Kissed A Girl, she'd been dropped from three record labels.

But the girl's got mettle, and she's proven that by bouncing back from the very public failure of her marriage to British comedian Russell Brand last year with more number one hits and a splashy 3-D concert movie.

Instead of shying away from the divorce, she has shone a spotlight on it with her latest singles Part of Me and Wide Awake - as well as in her movie Katy Perry: Part Of Me, in which the usually bright and bubbly Perry is seen in a few scenes breaking down backstage as her marriage crumbled.

"I wanted to show America that 'Look, yeah, I'm going through some of the same situation that most of America, or half of America, goes through and somehow I landed on my feet," she told US talk show host Jay Leno last month.

She produced and paid for the film, which cost US$12 million (S$15 million), herself. It opens here on Aug 23.

Like Canadian pop star Justin Bieber's 2011 concert movie Justin Bieber: Never Say Never, Katy Perry: Part Of Me is partly a behind-the-scenes look at what goes into the making of a successful tour, and partly a biography of the star.

Perry, who, according to her 91-year-old grandmother Ann was a "show-off" from young, started off as a gospel singer, recording her first album, Katy Hudson, when she was 15 in Nashville, Tennessee.

"I started kind of banging it across my parents' heads that I wanted to do this when I was nine," she said in a conversation with Saturday Night Live comedian Kristen Wiig for Interview magazine in March.

Impressed

But the country record failed, and she moved to Los Angeles, turning up on producer Glen Ballard's doorstep to get him to work with her, after being inspired by Alanis Morissette's breakthrough album, Jagged Little Pill, which Ballard produced.

While Ballard was impressed and took Perry under his wing, she still had to struggle through two more failed recording contracts, before finally being signed to Capitol Music Group in 2007.

She was 24 when I Kissed A Girl hit number one on the Billboard Hot 100 chart, the first of seven number ones she would eventually chalk up.

"When I first came to LA, I used to audition, and I had such fear because nobody really believed in my music," she told Interview. "I couldn't get anyone on my bandwagon. Now I have a confidence because my research shows that I should just really trust my instincts."

Discussing what went into her rise to success, Perry told Leno: "You don't have to be born into a situation, you don't have to come from something or possess something or look flawless - even though I like looking like this sometimes - you can just be you, and have a dream and plant the seed and water the root."

It's a message that's stuck with her fans, whose personal testaments she features in her movie.

For a while, the picture perfect pop star life was all hers.

Perry's second album, Teenage Dream, was churning out consecutive number one hits, and she had fallen in love with Brand after an acrimonious split from US rock band Gym Class Heroes' frontman Travie McCoy.

She and Brand, 37, tied the knot in a lavish ceremony in India in October 2010, and Perry embarked on her 124-date California Dreams Tour in early 2011.

But by the end of last year, the dream - or at least part of it - was dashed, when Brand filed for divorce in December, citing "irreconcilable differences".

It became official on July 16.

"Just because you're in the spotlight doesn't mean you get to dodge curveballs. They're actually bigger," she told Leno.

In an interview with US radio DJ Howard Stern last week, Brand said the marriage didn't work out because of the pair's busy schedules.

"I was really, really in love with her, but it was difficult to see each other," he said. "It was a lovely relationship...it mostly didn't work out for practical reasons."

Bad Blood

Still, there does seem to have been bad blood between the two.

Taking a leaf out of US country singer Taylor Swift's modus operandi, Perry's break-up has been hit-making fodder.

Both of her post-split singles Part Of Me and Wide Awake have been break-up anthems which directly reference her relationship with Brand, with Part Of Me giving her a sixth number one on the Billboard Hot 100 chart.

Brand, meanwhile, possibly let slip his true feelings about Perry at a taping of his new show Brand X in Los Angeles last week.

After bantering back and forth with a couple in the audience called Curtis and Katy, he said: "Anyway, enough of you. I've had enough a***-ache from people called Katy in the last year."

Both seem to have moved on.

Brand started dating Hungarian model Nikolett Barabas in March, and has been most recently linked to US actress Jordana Brewster's younger sister, Isabella.

Though Perry told USA Today earlier this month that she's "totally not looking (for love)" and is just " looking to heal", she been linked to English indie rock band Florence and the Machine's guitarist Robert Ackroyd, who is reportedly moving from the UK to Los Angeles to spend more time with her.

She has also said she's not looking to release an entire album of break-up songs.

"I wouldn't dedicate a whole record to that. That would be not so fun, and I'm still having fun," she said.

"My fairy tale has absolutely changed," she told USA Today. "I don't need the Prince Charming to have my own happy ending ... I can make the happy ending myself."