Katy Perry's new single makes her feel self-empowered.

The 28-year-old singer penned her pop anthem 'Roar' after a tumultuous year - during which she divorced comedian Russell Brand and embarked upon a rocky relationship with John Mayer - and says the track was like musical therapy.

She told the UK's Radio 1 DJ Scott Mills: ''It's a bit of a self-empowering type of song. I wrote it because I was sick of keeping all these feelings inside and now speaking up for myself, which cause a lot of resentment.

''Obviously I've been through a lot of therapy since my last record and that's what this is about.''

The song was released early after it leaked online on Saturday (10.08.13), while her chart rival Lady GaGa's new tune 'Applause' suffered a similar fate.

Following weeks of Gaga and Katy's fans battling it out on Twitter over whose comeback would be more successful, the eccentric singer decided to put an end to things.

Writing in a statement on her website, Gaga raged: ''I really want the second half of 2013 to mark a change in pop, when music is not mangled by trash talk and tabloids.

''I support pop music and more artists putting out new music just means more for music lovers to enjoy. Don't fight with Katy's fans, or anyone. STOP THE DRAMA. START THE MUSIC.

''Pop music is fun and these 'wars' are not at all what I'm about. I want people to focus on my new work, not gossip.''

Gaga also extended a virtual olive branch to Katy over Twitter, suggesting they team up to fight back at the hackers who leaked their songs.

She joked: ''Wanna grab some shovels and f--k up some hackers? @katyperry excited to hear your ROAR, sorry to hear about your truck crash!''

Katy returned the favour, replying: ''@ladygaga what a WILD weekend so far...claws out, paws up! Looking forward to puttin my hands up & making them touch too!''